Bio


Rod Ewing is the Frank Stanton Professor in Nuclear Security in the Center for International Security and Cooperation in the Freeman Spogli Institute for International Studies and a Professor in the Department of Geological Sciences in the School of Earth, Energy and Environmental Sciences at Stanford University. He is the Edward H. Kraus Distinguished University Professor Emeritus at the University of Michigan, where he was in three Departments: Earth & Environmental Sciences, Nuclear Engineering & Radiological Sciences, and Materials Science and Engineering. He is also a Regents' Emeritus Professor at the University of New Mexico.

Ewing received a B.S. degree in geology from Texas Christian University (1968, summa cum laude) and M.S. (l972) and Ph.D. (l974, with distinction) degrees from Stanford University where he held an NSF Fellowship. His graduate studies focused on an esoteric group of minerals, metamict Nb-Ta-Ti oxides, which are unusual because they have become amorphous due to radiation damage caused by the presence of radioactive elements. Over the past forty years, the early study of these unusual minerals has blossomed into a broadly based research program on radiation effects in complex ceramic materials. This has led to the development of techniques to predict the long-term behavior of materials, such as those used in radioactive waste disposal. He is the author or co-author of over 750 research publications and the editor or co-editor of 18 monographs, proceedings volumes or special issues of journals. He has published widely in mineralogy, geochemistry, materials science, nuclear materials, physics and chemistry in over 100 different ISI journals. He has been granted a patent for the development of a highly durable material for the immobilization of excess weapons plutonium.

Ewing has received the Hawley Medal of the Mineralogical Association of Canada in 1997 and 2002, a Guggenheim Fellowship in 2002, the Dana Medal of the Mineralogical Society of America in 2006, the Lomonosov Gold Medal of the Russian Academy of Sciences in 2006, a Honorary Doctorate from the Université Pierre et Marie Curie in 2007, Roebling Medal of the Mineralogical Society of America, and is a foreign Fellow of the Royal Society of Canada. He is also a fellow of the Geological Society of America, Mineralogical Society of America, American Geophysical Union, Geochemical Society and the European Association of Geochemistry, American Ceramic Society, the American Association for the Advancement of Science, Mineralogical Society of Great Britain and Ireland, and the Materials Research Society. He was elected to the National Academy of Engineering in 2017.

He has been president of the Mineralogical Society of America (2002) and the International Union of Materials Research Societies (1997-1998). Ewing has served on the Board of Directors of the Geochemical Society (2012-2015) and the Board of Governors of the Gemological Institute of America (2006-2015). He is a member of the Science and Security Board of the Bulletin of the Atomic Scientists and on the Editorial Board of Applied Physics Reviews . He is a founding Editor of the magazine Elements, which is now supported by 17 earth science societies, and a Founding Executive Editor of Geochemical Perspective Letters. He is a member of the Board of Earth Sciences and Resources of the National Academy of Science, Engineering and Medicine (2017-2020).

Professor Ewing is co-editor of and a contributing author of Radioactive Waste Forms for the Future (North-Holland Physics, Amsterdam, 1988) and Uncertainty Underground – Yucca Mountain and the Nation’s High-Level Nuclear Waste (MIT Press, 2006). He has served on eleven National Research Council committees for the National Academy of Sciences that have reviewed issues related to nuclear waste and nuclear weapons. He was appointed by President Obama to Chair the Nuclear Waste Technical Review Board (2012-2017).

Administrative Appointments


  • Co-Director, Center for International Security and Cooperation (2017 - 2024)
  • Co-Director, Mineral-X (2022 - Present)

Honors & Awards


  • William B. Heroy Jr. Award for Distinguished Service to AGI, American Geoscience Institute (2023)
  • Distinguished Public Service Medal, Mineralogical Society of America (2019)
  • Robert Cahn Award for research on nuclear materials, Journal of Nuclear Materials and NuMat Meeting (2018)
  • Election, National Academy of Engineering (2017)
  • Grandey Distinguished Lecture, Colorado School of Mines (2017)
  • Radiation Effects in Insulators Award for lifetime achievement, International Committee for REI (2017)
  • Baldwin Frontiers in Geology Distinguished Lecture, University of Miami Ohio (2016)
  • Director's Distinguished Lecture, Pacific Northwest National Laboratory (2016)
  • IMA Medal for Excellence in Mineralogical Research, International Mineralogical Association (2015)
  • Ian Campbell Medal for Superlative Service to the Geosciences, American Geoscience Institute (2015)
  • Roebling Medal, Mineralogical Society of America (2015)
  • Edward H. Kraus Distinguished University Professor Emeritus, University of Michigan (2014 - present)
  • Honorary Fellow, Mineralogical Society of Great Britain and Ireland (2013)
  • Ida Beam Distinguished Visiting Professorship, University of Iowa (2013)
  • Hallimond Lecture, Mineralogical Society of Great Britain and Ireland (2010)
  • Edward H. Kraus Distinguished University Professor, University of Michigan (2009 - 2013)
  • Fellow, Geochemical Society and the European Association for Geochemistry (2009)
  • Foreign Fellow, Royal Society of Canada (2009)
  • Fellow, American Ceramic Society (2008)
  • Fellow, Materials Research Society (2008)
  • Docteur Honoris Causa, Université Pierre et Marie Curie, Paris VII (2007)
  • Fellow, American Geophysical Union (2007)
  • Hamilton Visiting Scholar, Southern Methodist University (2007)
  • Award for Outstanding Editorial or Publishing Contributions, Association of Earth Science Editors (2006)
  • Dana Medal, Mineralogical Society of America (2006)
  • Lomonosov Great Gold Medal, Russian Academy of Sciences (2006)
  • Michel T. Halbouty Distinguished Lecturer, Geological Society of America (2006)
  • Umbgrove Lecture, Universiteit Utrecht, The Netherlands (2006)
  • Zussman Lecture, University of Manchester (2005)
  • Distinguished Lecturer, Mineralogical Society of America (2004 - 2005)
  • Fellow, American Association for the Advancement of Science (2004)
  • Fellowship, Guggenheim Foundation (2002)
  • Hawley Medal, Mineralogical Association of Canada (2002)
  • Regents' Professor Emeritus, University of New Mexico (1997 - present)
  • Fellowship, Yamada Foundation, University of Tokyo (1997)
  • Hawley Medal, Mineralogical Association of Canada (1997)
  • Regents' Professor, University of New Mexico (1993 - 1997)
  • Fellow, Geological Society of America (1985)
  • Fellow, Mineralogical Society of America (1983)

Boards, Advisory Committees, Professional Organizations


  • Past-President, American Geoscience Institute (2019 - 2020)
  • President, American Geoscience Institute (2018 - 2019)
  • Member, Board on Earth Sciences and Resources, National Research Council (2017 - 2022)
  • President-Elect, American Geoscience Institute (2017 - 2018)
  • Member, Editorial Board of Applied Physics Review (2014 - 2018)
  • Executive Editor, Geochemical Perspectives Letters (2014 - 2016)
  • Member, Science and Security Board of the Bulletin of Atomic Scientists (2013 - Present)
  • Director, Board of Directors of the Geochemical Society (2012 - 2015)
  • Chairman, Nuclear Waste Technical Review Board (2011 - 2017)
  • Principal Editor, Nano LIFE (2010 - Present)
  • Governor, Board of Governors of the Gemological Institute of America (2006 - 2015)
  • Founding Editor, Elements magazine (2003 - 2004)
  • President, Mineralogical Society of America (2002 - 2003)
  • President, International Union of Materials Research Societies (1997 - 1998)

Professional Education


  • Ph.D., Stanford University, Mineralogy (1974)
  • M.S., Stanford University, Mineralogy (1972)
  • B.S., Texas Christian University, Geology (1968)

Patents


  • Rodney Ewing, Werner Lutze, William J. Weber. "United States Patent 5,545,797 Method of immobilizing weapons plutonium to provide a durable, disposal waste product", University of New Mexico, Sep 13, 1996

All Publications


  • Crystal chemistry and thermodynamic properties of zircon structure-type materials AMERICAN MINERALOGIST Strzelecki, A. C., Zhao, X., Estevenon, P., Xu, H., Dacheux, N., Ewing, R. C., Guo, X. 2024; 109 (2): 225-242
  • Nuclear waste Educator's workshop: What and how do we teach about nuclear waste? Journal of environmental radioactivity Wainwright, H. M., Powell, B. A., Hoover, M. E., Ayoub, A., Atz, M., Benson, C., Borrelli, R. A., Djokic, D., Eddy-Dilek, C. A., Ermakova, D., Hayes, R., Higley, K., Krahn, S., Lagos, L., Landsberger, S., Leggett, C., Regalbuto, M., Roy, W., Shuller-Nickles, L., Ewing, R. C. 2023; 270: 107288

    Abstract

    A workshop was held at the Massachusetts Institute of Technology (MIT) on July 25th and 26th, 2022. The objective was to develop a blueprint for educating next-generation engineers and scientists about nuclear waste management and disposal, which requires knowledge from diverse disciplines, including nuclear, chemical, civil, environmental, and geological science and engineering. The 49 participants included university professors, researchers, industry experts, and government officials from different areas. First, we have developed a list of key fundamental knowledge on waste management and disposal across the nuclear fuel cycle. In addition, we discussed strategies on how to teach students with diverse backgrounds through innovative teaching strategies as well as how to attract students into this area. Through the workshop, we identified the critical needs to (1) develop community resources for nuclear waste education; (2) synthesize historical perspectives, including past contamination and the management of general hazardous waste; (3) emphasize a complete life-cycle perspective, including proper waste management as the key component for energy sustainability; (4) teach students how to communicate about the key facts and risks to technical and non-technical audiences; and (5) accelerate the use of the state-of-art-technologies to attract and retain a young workforce. Furthermore, we aim to build a diverse, inclusive community that supports students in developing their own narratives about nuclear waste, particularly in recognizing that antagonistic views have been important to improving safety and protecting public health and the environment.

    View details for DOI 10.1016/j.jenvrad.2023.107288

    View details for PubMedID 37722230

  • Probing structural disorder in zircon by electron backscatter diffraction (EBSD): Radiation damage and Kikuchi pattern JOURNAL OF NUCLEAR MATERIALS Beirau, T., Kilian, R., Stipp, M., Ewing, R. C. 2023; 581
  • Reimagining US rare earth production: Domestic failures and the decline of US rare earth production dominance - Lessons learned and recommendations RESOURCES POLICY Park, S., Tracy, C. L., Ewing, R. C. 2023; 85
  • Unexpectedly narrower track diameter at site of fission event EARTH AND PLANETARY SCIENCE LETTERS Li, W., Shen, Y., Zhou, Y., Zhai, P., Nan, S., Liu, J., Ewing, R. C. 2023; 616
  • Phase transformation and radiation resistance of B-site high entropy pyrochlores SCRIPTA MATERIALIA Li, Y., Lei, Y., Zhao, S., Xiao, H., Liu, H., Wang, Y., Luo, Y., Zhang, J., Wang, J., Ewing, R. C., Wang, C. 2023; 229
  • Systematic study of short- and long-range correlations in RE3TaO7 weberite-type compounds by neutron total scattering and X-ray diffraction JOURNAL OF MATERIALS CHEMISTRY A Gussev, I. M., O'Quinn, E. C., Tucker, M., Ewing, R. C., Overstreet, C., Neuefeind, J., Everett, M., Zhang, Q., Sprouster, D., Olds, D., Baldinozzi, G., Lang, M. 2023

    View details for DOI 10.1039/d3ta01042b

    View details for Web of Science ID 000962707500001

  • Mining for the Bomb: The Vulnerability of Buried Plutonium to Clandestine Recovery SCIENCE & GLOBAL SECURITY Tracy, C. L., Ewing, R. C. 2023
  • Effect of Dipole Interactions on Blocking Temperature and Relaxation Dynamics of Superparamagnetic Iron-Oxide (Fe3O4) Nanoparticle Systems. Materials (Basel, Switzerland) Sadat, M. E., Bud'ko, S. L., Ewing, R. C., Xu, H., Pauletti, G. M., Mast, D. B., Shi, D. 2023; 16 (2)

    Abstract

    The effects of dipole interactions on magnetic nanoparticle magnetization and relaxation dynamics were investigated using five nanoparticle (NP) systems with different surfactants, carrier liquids, size distributions, inter-particle spacing, and NP confinement. Dipole interactions were found to play a crucial role in modifying the blocking temperature behavior of the superparamagnetic nanoparticles, where stronger interactions were found to increase the blocking temperatures. Consequently, the blocking temperature of a densely packed nanoparticle system with stronger dipolar interactions was found to be substantially higher than those of the discrete nanoparticle systems. The frequencies of the dominant relaxation mechanisms were determined by magnetic susceptibility measurements in the frequency range of 100 Hz-7 GHz. The loss mechanisms were identified in terms of Brownian relaxation (1 kHz-10 kHz) and gyromagnetic resonance of Fe3O4 (~1.12 GHz). It was observed that the microwave absorption of the Fe3O4 nanoparticles depend on the local environment surrounding the NPs, as well as the long-range dipole-dipole interactions. These significant findings will be profoundly important in magnetic hyperthermia medical therapeutics and energy applications.

    View details for DOI 10.3390/ma16020496

    View details for PubMedID 36676230

  • US Legal and Regulatory Framework for Nuclear Waste from Present and Future Reactors and Their Fuel Cycles ANNUAL REVIEW OF ENVIRONMENT AND RESOURCES Park, S., Ewing, R. C. 2023; 48: 713-736
  • Critical metal resources in Democratic People's Republic of Korea INTERNATIONAL GEOLOGY REVIEW Park, S., McNulty, T. P., Ewing, R. C. 2022
  • THE GOLDEN AGE OF MINERALOGY: REFLECTIONS BY IMA MEDALISTS (Part II) International Mineralogical Association (IMA) ELEMENTS Hawthorne, F. C., Sobolev, N. C., Ewing, R. C., Brown Jr, G. E., Hazen, R. M. 2022; 18 (6): 365-367
  • Thermal annealing of fission and ion tracks in epidote PHYSICS AND CHEMISTRY OF MINERALS Nakasuga, W. M., Li, W., Chen, C., Dumitru, T. A., Skuratov, V. A., Ewing, R. C. 2022; 49 (7)
  • Nuclear waste from small modular reactors. Proceedings of the National Academy of Sciences of the United States of America Krall, L. M., Macfarlane, A. M., Ewing, R. C. 2022; 119 (23): e2111833119

    Abstract

    SignificanceSmall modular reactors (SMRs), proposed as the future of nuclear energy, have purported cost and safety advantages over existing gigawatt-scale light water reactors (LWRs). However, few studies have assessed the implications of SMRs for the back end of the nuclear fuel cycle. The low-, intermediate-, and high-level waste stream characterization presented here reveals that SMRs will produce more voluminous and chemically/physically reactive waste than LWRs, which will impact options for the management and disposal of this waste. Although the analysis focuses on only three of dozens of proposed SMR designs, the intrinsically higher neutron leakage associated with SMRs suggests that most designs are inferior to LWRs with respect to the generation, management, and final disposal of key radionuclides in nuclear waste.

    View details for DOI 10.1073/pnas.2111833119

    View details for PubMedID 35639689

  • Recent advances in the global rare-earth supply chain MRS BULLETIN Pawar, G., Ewing, R. C. 2022; 47 (3): 244-249
  • Volatilization of B4C control rods in Fukushima Daiichi nuclear reactors during meltdown: B-Li isotopic signatures in cesium-rich microparticles. Journal of hazardous materials Fueda, K., Takami, R., Minomo, K., Morooka, K., Horie, K., Takehara, M., Yamasaki, S., Saito, T., Shiotsu, H., Ohnuki, T., Law, G. T., Grambow, B., Ewing, R. C., Utsunomiya, S. 1800; 428: 128214

    Abstract

    Boron carbide control rods remain in the fuel debris of the damaged reactors in the Fukushima Daiichi Nuclear Power Plant, potentially preventing re-criticality; however, the state and stability of the control rods remain unknown. Sensitive high-resolution ion microprobe analyses have revealed B-Li isotopic signatures in radioactive Cs-rich microparticles (CsMPs) that formed by volatilization and condensation of Si-oxides during the meltdowns. The CsMPs contain 1518-6733mgkg-1 of 10+11B and 11.99-1213mgkg-1 of 7Li. The 11B/10B (4.15-4.21) and 7Li/6Li (213-406) isotopic ratios are greater than natural abundances (~4.05 and ~12.5, respectively), indicating that 10B(n,alpha)7Li reactions occurred in B4C prior to the meltdowns. The total amount of B released with CsMPs was estimated to be 0.024-62g, suggesting that essentially all B remains in reactor Units 2 and/or 3 and is enough to prevent re-criticality; however, the heterogeneous distribution of B needs to be considered during decommissioning.

    View details for DOI 10.1016/j.jhazmat.2022.128214

    View details for PubMedID 35042164

  • Machine learning improves satellite imagery analysis of North Korean nuclear activity BULLETIN OF THE ATOMIC SCIENTISTS Park, S., Puccioni, A., Ewing, R. C. 2022; 78 (1): 26-37
  • Phase stability of pre-irradiated CeO2 with swift heavy ions under high pressure up to 45 GPa JOURNAL OF THE AMERICAN CERAMIC SOCIETY Lan, J., Zhai, P., Nan, S., Xu, L., Niu, J., Tian, C., Li, Z., Li, W., Liu, J., Ewing, R. 2021

    View details for DOI 10.1111/jace.18273

    View details for Web of Science ID 000731328600001

  • Fracture toughness of radiation-damaged zircon studied by nanoindentation pillar-splitting APPLIED PHYSICS LETTERS Beirau, T., Rossi, E., Sebastiani, M., Oliver, W. C., Poellmann, H., Ewing, R. C. 2021; 119 (23)

    View details for DOI 10.1063/5.0070597

    View details for Web of Science ID 000729403700002

  • Assessing Uranium Ore Processing Activities Using Satellite Imagery at Pyongsan in the Democratic People's Republic of Korea SCIENCE & GLOBAL SECURITY Park, S., Ewing, R. C., Terry McNulty, Puccioni, A. 2021
  • New highly radioactive particles derived from Fukushima Daiichi Reactor Unit 1: Properties and environmental impacts. The Science of the total environment Morooka, K., Kurihara, E., Takehara, M., Takami, R., Fueda, K., Horie, K., Takehara, M., Yamasaki, S., Ohnuki, T., Grambow, B., Law, G. T., Ang, J. W., Bower, W. R., Parker, J., Ewing, R. C., Utsunomiya, S. 2021; 773: 145639

    Abstract

    A contaminated zone elongated toward Futaba Town, north-northwest of the Fukushima Daiichi Nuclear Power Plant (FDNPP), contains highly radioactive particles released from reactor Unit 1. There are uncertainties associated with the physio-chemical properties and environmental impacts of these particles. In this study, 31 radioactive particles were isolated from surface soils collected 3.9km north-northwest of the FDNPP. Two of these particles have the highest particle-associated 134+137Cs activity ever reported for Fukushima (6.1*105 and 2.5*106Bq per particle after decay-correction to March 2011). The new, highly-radioactive particle labeled FTB1 is an aggregate of flaky silicate nanoparticles with an amorphous structure containing ~0.8wt% Cs, occasionally associated with SiO2 and TiO2 inclusions. FTB1 likely originates from the reactor building, which was damaged by a H2 explosion, after adsorbing volatilized Cs. The 134+137Cs activity in the other highly radioactive particle labeled FTB26 exceeded 106Bq. FTB26 has a glassy carbon core and a surface that is embedded with numerous micro-particles: Pb-Sn alloy, fibrous Al-silicate, Ca-carbonate or hydroxide, and quartz. The isotopic signatures of the micro-particles indicate neutron capture by B, Cs volatilization, and adsorption of natural Ba. The composition of the micro-particles on FTB26 reflects the composition of airborne particles at the moment of the H2 explosion. Owing to their large size, the health effects of the highly radioactive particles are likely limited to external radiation during static contact with skin; the highly radioactive particles are thus expected to have negligible health impacts for humans. By investigating the mobility of the highly radioactive particles, we can better understand how the radiation dose transfers through environments impacted by Unit 1. The highly radioactive particles also provide insights into the atmospheric conditions at the time of the Unit 1 explosion and the physio-chemical phenomena that occurred during reactor meltdown.

    View details for DOI 10.1016/j.scitotenv.2021.145639

    View details for PubMedID 33940743

  • Alpha-decay induced shortening of fission tracks simulated by in situ ion irradiation GEOCHIMICA ET COSMOCHIMICA ACTA Li, W., Cheng, Y., Feng, L., Niu, J., Liu, Y., Skuratov, V. A., Zdorovets, M., Boatner, L. A., Ewing, R. C. 2021; 299: 1–14
  • Socio-technical multi-criteria evaluation of long-term spent nuclear fuel management strategies: A framework and method. The Science of the total environment Diaz-Maurin, F. n., Yu, J. n., Ewing, R. C. 2021; 777: 146086

    Abstract

    In the absence of a federal geologic repository or consolidated, interim storage in the United States, commercial spent fuel will remain stranded at some 75 sites across the country. Currently, these include 18 "orphaned sites" where spent fuel has been left at decommissioned reactor sites. In this context, local communities living close to decommissioned nuclear power plants are increasingly concerned about this legacy of nuclear power production and are seeking alternative strategies to move the spent fuel away from those sites. In this paper, we present a framework and method for the socio-technical multi-criteria evaluation (STMCE) of spent fuel management strategies. The STMCE approach consists of (i) a multi-criteria evaluation that provides an ordinal ranking of alternatives based on a list of criterion measurements; and (ii) a social impact analysis that provides an outranking of options based on the assessment of their impact on concerned social actors. STMCE can handle quantitative, qualitative or both types of information. It can also integrate stochastic uncertainty on criteria measurements and fuzzy uncertainty on assessments of social impacts. We conducted an application of the STMCE method using data from the decommissioned San Onofre Nuclear Generating Station (SONGS) in California. This example intends to facilitate the preparation of stakeholder engagement activities on spent fuel management using the STMCE approach. The STMCE method provides an effective way to compare spent fuel management strategies and support the search for compromise solutions. We conclude by discussing the potential impact that such an approach could have on the management of commercial spent fuel in the United States.

    View details for DOI 10.1016/j.scitotenv.2021.146086

    View details for PubMedID 33677296

  • The Role of Water and Hydroxyl Groups in the Structures of Stetindite and Coffinite, MSiO4 (M = Ce, U). Inorganic chemistry Strzelecki, A. C., Barral, T. n., Estevenon, P. n., Mesbah, A. n., Goncharov, V. n., Baker, J. n., Bai, J. n., Clavier, N. n., Szenknect, S. n., Migdisov, A. n., Xu, H. n., Ewing, R. C., Dacheux, N. n., Guo, X. n. 2021

    Abstract

    Orthosilicates adopt the zircon structure types (I41/amd), consisting of isolated SiO4 tetrahedra joined by A-site metal cations, such as Ce and U. They are of significant interest in the fields of geochemistry, mineralogy, nuclear waste form development, and material science. Stetindite (CeSiO4) and coffinite (USiO4) can be formed under hydrothermal conditions despite both being thermodynamically metastable. Water has been hypothesized to play a significant role in stabilizing and forming these orthosilicate phases, though little experimental evidence exists. To understand the effects of hydration or hydroxylation on these orthosilicates, in situ high-temperature synchrotron and laboratory-based X-ray diffraction was conducted from 25 to ∼850 °C. Stetindite maintains its I41/amd symmetry with increasing temperature but exhibits a discontinuous expansion along the a-axis during heating, presumably due to the removal of water confined in the [001] channels, which shrink against thermal expansion along the a-axis. Additional in situ high-temperature Raman and Fourier transform infrared spectroscopy also confirmed the presence of the confined water. Coffinite was also found to expand nonlinearly up to 600 °C and then thermally decompose into a mixture of UO2 and SiO2. A combination of dehydration and dehydroxylation is proposed for explaining the thermal behavior of coffinite synthesized hydrothermally. Additionally, we investigated high-temperature structures of two coffinite-thorite solid solutions, uranothorite (U x Th1-xSiO4), which displayed complex variations in composition during heating that was attributed to the negative enthalpy of mixing. Lastly, for the first time, the coefficients of thermal expansion of CeSiO4, USiO4, U0.46Th0.54SiO4, and U0.9Th0.1SiO4 were determined to be αV = 14.49 × 10-6, 14.29 × 10-6, 17.21 × 10-6, and 17.23 × 10-6 °C-1, respectively.

    View details for DOI 10.1021/acs.inorgchem.0c02757

    View details for PubMedID 33393766

  • Radiation effects in M(n+1)AX(n) phases APPLIED PHYSICS REVIEWS Wang, C., Tracy, C. L., Ewing, R. C. 2020; 7 (4)

    View details for DOI 10.1063/5.0019284

    View details for Web of Science ID 000598860900001

  • Reflections of a Scientist Laboring in the Nuclear Waste Field. Ground water Ewing, R. C. 2020

    View details for DOI 10.1111/gwat.13058

    View details for PubMedID 33169361

  • Disorder in Ho2Ti2-xZrxO7: pyrochlore to defect fluorite solid solution series RSC ADVANCES Drey, D. L., O'Quinn, E. C., Subramani, T., Lilova, K., Baldinozzi, G., Gussev, I. M., Fuentes, A. F., Neuefeind, J. C., Everett, M., Sprouster, D., Navrotsky, A., Ewing, R. C., Lang, M. 2020; 10 (57): 34632–50

    View details for DOI 10.1039/d0ra07118h

    View details for Web of Science ID 000572299600031

  • Disorder in Ho2Ti2-x Zr x O7: pyrochlore to defect fluorite solid solution series. RSC advances Drey, D. L., O'Quinn, E. C., Subramani, T., Lilova, K., Baldinozzi, G., Gussev, I. M., Fuentes, A. F., Neuefeind, J. C., Everett, M., Sprouster, D., Navrotsky, A., Ewing, R. C., Lang, M. 2020; 10 (57): 34632-34650

    Abstract

    Pyrochlore (A2B2O7) is an important, isometric structure-type because of its large variety of compositions and structural derivatives that are generally related to different disordering mechanisms at various spatial scales. The disordering is key to understanding variations in properties, such as magnetic behavior or ionic conduction. Neutron and X-ray total scattering methods were used to investigate the degree of structural disorder in the Ho2Ti2-x Zr x O7 (x = 0.0-2.0, Δx = 0.25) solid solution series as a function of the Zr-content, x. Ordered pyrochlores (Fd3̄m) disorder to defect fluorite (Fm3̄m) via cation and anion disordering. Total scattering experiments with sensitivity to the cation and anion sublattices provide unique insight into the underlying atomic processes. Using simultaneous Rietveld refinement (long-range structure) and small-box refinement PDF analysis (short-range structure), we show that the series undergoes a rapid transformation from pyrochlore to defect fluorite at x ≈ 1.2, while the short-range structure exhibits a linear increase in a local weberite-type phase, C2221, over the entire composition range. Enthalpies of formation from the oxides determined using high temperature oxide melt solution calorimetry support the structural data and provide insight into the effect of local ordering on the energetics of disorder. The measured enthalpies of mixing are negative and are fit by a regular solution parameter of W = -31.8 ± 3.7 kJ mol-1. However, the extensive short-range ordering determined from the structural analysis strongly suggests that the entropies of mixing must be far less positive than implied by the random mixing of a regular solution. We propose a local disordering scheme involving the pyrochlore 48f to 8a site oxygen Frenkel defect that creates 7-coordinated Zr sites contained within local weberite-type coherent nanodomains. Thus, the solid solution is best described as a mixture of two phases, with the weberite-type nanodomains triggering the long-range structural transformation to defect fluorite after accumulation above a critical concentration (50% Ti replaced by Zr).

    View details for DOI 10.1039/d0ra07118h

    View details for PubMedID 35514412

    View details for PubMedCentralID PMC9056788

  • Local order of orthorhombic weberite-type Y3TaO7 as determined by neutron total scattering and density functional theory calculations ACTA MATERIALIA Gussev, I. M., O'Quinn, E. C., Baldinozzi, G., Neuefeind, J., Ewing, R. C., Zhang, F., Lang, M. 2020; 196: 704–9
  • Thermodynamics of CeSiO4: Implications for Actinide Orthosilicates. Inorganic chemistry Strzelecki, A. C., Bourgeois, C., Kriegsman, K. W., Estevenon, P., Wei, N., Szenknect, S., Mesbah, A., Wu, D., Ewing, R. C., Dacheux, N., Guo, X. 2020

    Abstract

    Zircon (ZrSiO4, I41/amd) can accommodate actinides, such as thorium, uranium, and plutonium. The zircon structure has been determined for several of the end-member compositions of other actinides, such as plutonium and neptunium. However, the thermodynamic properties of these actinide zircon structure types are largely unknown due to the difficulties in synthesizing these materials and handling transuranium actinides. Thus, we have completed a thermodynamic study of cerium orthosilicate, stetindite (CeSiO4), a surrogate of PuSiO4. For the first time, the standard enthalpy of formation of CeSiO4 was obtained by high temperature oxide melt solution calorimetry to be -1971.9 ± 3.6 kJ/mol. Stetindite is energetically metastable with respect to CeO2 and SiO2 by 27.5 ± 3.1 kJ/mol. The metastability explains the rarity of the natural occurrence of stetindite and the difficulty of its synthesis. Applying the obtained enthalpy of formation of CeSiO4 from this work, along with those previously reported for USiO4 and ThSiO4, we developed an empirical energetic relation for actinide orthosilicates. The predicted enthalpies of formation of AnSiO4 are then determined with a discussion of future strategies for efficiently immobilizing Pu or minor actinides in the zircon structure.

    View details for DOI 10.1021/acs.inorgchem.0c01476

    View details for PubMedID 32871073

  • Geologic Analysis of the Democratic People's Republic of Korea's Uranium Resources and Mines SCIENCE & GLOBAL SECURITY Park, S., Puccioni, A., Tracy, C. L., Serbin, E., Ewing, R. C. 2020
  • Predicting short-range order and correlated phenomena in disordered crystalline materials. Science advances O'Quinn, E. C., Sickafus, K. E., Ewing, R. C., Baldinozzi, G., Neuefeind, J. C., Tucker, M. G., Fuentes, A. F., Drey, D., Lang, M. K. 2020; 6 (35): eabc2758

    Abstract

    Disordered crystalline materials are used in a wide variety of energy-related technologies. Recent results from neutron total scattering experiments have shown that the atomic arrangements of many disordered crystalline materials are not random nor are they represented by the long-range structure observed from diffraction experiments. Despite the importance of disordered materials and the impact of disorder on the expression of physical properties, the underlying fundamental atomic-scale rules of disordering are not currently well understood. Here, we report that heterogeneous disordering (and associated structural distortions) can be understood by the straightforward application of Pauling's rules (1929). This insight, corroborated by first principles calculations, can be used to predict the short-range, atomic-scale changes that result from structural disordering induced by extreme conditions associated with energy-related applications, such as high temperature, high pressure, and intense radiation fields.

    View details for DOI 10.1126/sciadv.abc2758

    View details for PubMedID 32923649

  • Coffinite formation from UO2+x. Scientific reports Szenknect, S., Alby, D., Lopez Garcia, M., Wang, C., Podor, R., Miserque, F., Mesbah, A., Duro, L., Zetterstrom Evins, L., Dacheux, N., Bruno, J., Ewing, R. C. 2020; 10 (1): 12168

    Abstract

    Most of the highly radioactive spent nuclear fuel (SNF) around the world is destined for final disposal in deep-mined geological repositories. At the end of the fuel's useful life in a reactor, about 96% of the SNF is still UO2. Thus, the behaviour of UO2 in SNF must be understood and evaluated under the weathering conditions of geologic disposal, which extend to periods of hundreds of thousands of years. There is ample evidence from nature that many uranium deposits have experienced conditions for which the formation of coffinite, USiO4, has been favoured over uraninite, UO2+x, during subsequent alteration events. Thus, coffinite is an important alteration product of the UO2 in SNF. Here, we present the first evidence of the formation of coffinite on the surface of UO2 at the time scale of laboratory experiments in a solution saturated with respect to amorphous silica at pH=9, room temperature and under anoxic conditions.

    View details for DOI 10.1038/s41598-020-69161-1

    View details for PubMedID 32699386

  • Particulate plutonium released from the Fukushima Daiichi meltdowns. The Science of the total environment Kurihara, E., Takehara, M., Suetake, M., Ikehara, R., Komiya, T., Morooka, K., Takami, R., Yamasaki, S., Ohnuki, T., Horie, K., Takehara, M., Law, G. T., Bower, W., W Mosselmans, J. F., Warnicke, P., Grambow, B., Ewing, R. C., Utsunomiya, S. 2020; 743: 140539

    Abstract

    Traces of Pu have been detected in material released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March of 2011; however, to date the physical and chemical form of the Pu have remained unknown. Here we report the discovery of particulate Pu associated with cesium-rich microparticles (CsMPs) that formed in and were released from the reactors during the FDNPP meltdowns. The Cs-pollucite-based CsMP contained discrete U(IV)O2 nanoparticles, <~10nm, one of which is enriched in Pu adjacent to fragments of Zr-cladding. The isotope ratios, 235U/238U, 240Pu/239Pu, and 242Pu/239Pu, of the CsMPs were determined to be ~0.0193, ~0.347, and ~0.065, respectively, which are consistent with the calculated isotopic ratios of irradiated-fuel fragments. Thus, considering the regional distribution of CsMPs, the long-distance dispersion of Pu from FNDPP is attributed to the transport by CsMPs that have incorporated nanoscale fuel fragments prior to their dispersion up to 230km away from the Fukushima Daiichi reactor site.

    View details for DOI 10.1016/j.scitotenv.2020.140539

    View details for PubMedID 32663681

  • Structural evolution of Lu(2-x)Ce(x)Ti(2)O(7)pyrochlores under 400 keV Ne irradiation JOURNAL OF THE AMERICAN CERAMIC SOCIETY Xia, Y., Yang, D., Chen, C., Hao, Y., Ewing, R. C., Li, Y. 2020

    View details for DOI 10.1111/jace.17290

    View details for Web of Science ID 000541227400001

  • Processing of Soft Magnetic Fine Powders Directly From As-Spun Partial Crystalline Fe < sub > 77 </sub > Ni < sub > 5.5 </sub > Co < sub > 5.5 </sub > Zr < sub > 7 </sub > B < sub > 4 </sub > Cu Ribbon via Ball Mill Without Devitrification IEEE TRANSACTIONS ON MAGNETICS Thomas, S. V., Willard, M. A., Martone, A., Heben, M. J., Solomon, C., Welton, A., Boolchand, P., Ewing, R. C., Wang, C., Bud'ko, S. L., Shi, D. 2020; 56 (6)
  • Acceptance of Distinguished Public Service Award of the Mineralogical Society of America for 2019 AMERICAN MINERALOGIST Ewing, R. C. 2020; 105 (5): 774–75
  • Nanocrystallites via Direct Melt Spinning of Fe77Ni5.5Co5.5Zr7B4Cu for Enhanced Magnetic Softness PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE Thomas, S. V., Willard, M. A., Martone, A., Heben, M. J., Solomon, V., Welton, A., Boolchand, P., Ewing, R. C., Wang, C., Bud'ko, S. L., Song, J., Shi, D. 2020
  • Annealing of ion tracks in apatite under pressure characterized in situ by small angle x-ray scattering. Scientific reports Schauries, D., Afra, B., Mota-Santiago, P., Trautmann, C., Lang, M., Ewing, R. C., Kirby, N., Kluth, P. 2020; 10 (1): 1367

    Abstract

    Fission track thermochronology is routinely used to investigate the thermal history of sedimentary basins, as well as tectonic uplift and denudation rates. While the effect of temperature on fission track annealing has been studied extensively to calibrate the application of the technique, the effect of pressure during annealing is generally considered to be negligible. However, a previous study suggested elevated pressure results in a significantly different annealing behaviour that was previously unknown. Here, we present a method to study track annealing in situ under high pressure by using synchrotron-based small angle x-ray scattering (SAXS). To simulate fission tracks in a controlled environment, ion tracks were created in apatite from Durango, Mexico using 2GeV Au or Bi ions provided by an ion accelerator facility. Samples were annealed at 250°C at approximately 1GPa pressure using diamond anvil cells (DACs) with heating capabilities. Additional in situ annealing experiments at ambient pressure and temperatures between 320 and 390°C were performed for comparison. At elevated pressure a significantly accelerated annealing rate of the tracks was observed compared with annealing at ambient pressure. However, when extrapolated to geologically relevant temperatures and pressures, the effects become very small. The measurement methodology presented provides a new avenue to study materials behaviour in extreme environments.

    View details for DOI 10.1038/s41598-020-57600-y

    View details for PubMedID 31992739

  • Facile diamond synthesis from lower diamondoids. Science advances Park, S. n., Abate, I. I., Liu, J. n., Wang, C. n., Dahl, J. E., Carlson, R. M., Yang, L. n., Prakapenka, V. B., Greenberg, E. n., Devereaux, T. P., Jia, C. n., Ewing, R. C., Mao, W. L., Lin, Y. n. 2020; 6 (8): eaay9405

    Abstract

    Carbon-based nanomaterials have exceptional properties that make them attractive for a variety of technological applications. Here, we report on the use of diamondoids (diamond-like, saturated hydrocarbons) as promising precursors for laser-induced high-pressure, high-temperature diamond synthesis. The lowest pressure and temperature (P-T) conditions that yielded diamond were 12 GPa (at ~2000 K) and 900 K (at ~20 GPa), respectively. This represents a substantially reduced transformation barrier compared with diamond synthesis from conventional (hydro)carbon allotropes, owing to the similarities in the structure and full sp3 hybridization of diamondoids and bulk diamond. At 20 GPa, diamondoid-to-diamond conversion occurs rapidly within <19 μs. Molecular dynamics simulations indicate that once dehydrogenated, the remaining diamondoid carbon cages reconstruct themselves into diamond-like structures at high P-T. This study is the first successful mapping of the P-T conditions and onset timing of the diamondoid-to-diamond conversion and elucidates the physical and chemical factors that facilitate diamond synthesis.

    View details for DOI 10.1126/sciadv.aay9405

    View details for PubMedID 32128417

    View details for PubMedCentralID PMC7034983

  • Application of Electron Microscopy to Understanding Colloid-Facilitated Transport of Radionuclides at the Mayak Production Association Facility, Near Lake Karachai, Russia BEHAVIOR OF RADIONUCLIDES IN THE ENVIRONMENT I Utsunomiya, S., Yokoo, H., Oki, T., Kawamoto, K., Takeda, A., Wang, H., Ewing, R. C., Kato, K., Konoplev, A., Kalmykov, S. N. 2020: 177-200
  • Integration of the Back-end of the Nuclear Fuel Cycle: An Overview MRS ADVANCES Diaz-Maurin, F., Ewing, R. C. 2020; 5 (5-6): 253–64
  • Effects of irradiation temperature on the response of CeO2, ThO2, and UO2 to highly ionizing radiation JOURNAL OF NUCLEAR MATERIALS Cureton, W. E., Palomares, R., Tracy, C. L., O'Quinn, E. C., Walters, J., Zdorovets, M., Ewing, R. C., Toulemonde, M., Lang, M. 2019; 525: 83–91
  • Mechanical and structural properties of radiation-damaged allanite-(Ce) and the effects of thermal annealing PHYSICS AND CHEMISTRY OF MINERALS Reissner, C. E., Bismayer, U., Kern, D., Reissner, M., Park, S., Zhang, J., Ewing, R. C., Shelyug, A., Navrotsky, A., Paulmann, C., Skoda, R., Groat, L. A., Poellmann, H., Beirau, T. 2019; 46 (10): 921–33
  • Abundance and distribution of radioactive cesium-rich microparticles released from the Fukushima Daiichi Nuclear Power Plant into the environment. Chemosphere Ikehara, R., Morooka, K., Suetake, M., Komiya, T., Kurihara, E., Takehara, M., Takami, R., Kino, C., Horie, K., Takehara, M., Yamasaki, S., Ohnuki, T., Law, G. T., Bower, W., Grambow, B., Ewing, R. C., Utsunomiya, S. 2019; 241: 125019

    Abstract

    The abundance and distribution of highly radioactive cesium-rich microparticles (CsMPs) that were released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) during the first stage of the nuclear disaster in March 2011 are described for 20 surface soils collected around the FDNPP. Based on the spatial distribution of the numbers (particles/g) and radioactive fraction (RF) of the CsMPs in surface soil, which is defined as the sum of the CsMP radioactivity (in Bq) divided by the total radioactivity (in Bq) of the soil sample, three regions of particular interest have been identified: i.) near-northwest (N-NW), ii.) far-northwest (F-NW), and iii.) southwest (SW). In these areas, the number and RF of CsMPs were determined to be 22.1-101 particles/g and 15.4-34.0%, 24.3-64.8 particles/g and 36.7-37.4%, and 0.869-8.00 particles/g and 27.6-80.2%, respectively. These distributions are consistent with the plume trajectories of material released from the FDNPP on March 14, 2011, in the late afternoon through to the late afternoon of March 15, 2011, indicating that the CsMPs formed only during this short period. Unit 3 is the most plausible source of the CsMPs at the beginning of the release based on an analysis of the sequence of release events. The lower RF values in the N-NW region indicate a larger influence from subsequent plumes that mainly consisted of soluble Cs species formed simultaneously with precipitation. The quantitative map of the distribution of CsMPs provides an important understanding of CsMP dispersion dynamics and can be used to assess risks in inhabited regions.

    View details for DOI 10.1016/j.chemosphere.2019.125019

    View details for PubMedID 31610456

  • Radiation-damage in multi-layered zircon: Mechanical properties APPLIED PHYSICS LETTERS Beirau, T., Oliver, W. C., Reissner, C. E., Nix, W. D., Poellmann, H., Ewing, R. C. 2019; 115 (8)

    View details for DOI 10.1063/1.5119207

    View details for Web of Science ID 000482474300052

  • Anomalous behavior of nonequilibrium excitations in UO2 PHYSICAL REVIEW B Rittman, D. R., Teitelbaum, S. W., Reis, D. A., Mao, W. L., Ewing, R. C. 2019; 99 (13)
  • Phase transformations of Al-bearing high-entropy alloys AlxCoCrFeNi (x=0, 0.1, 0.3, 0.75, 1.5) at high pressure APPLIED PHYSICS LETTERS Wang, C., Tracy, C. L., Park, S., Liu, J., Ke, F., Zhang, F., Yang, T., Xia, S., Li, C., Wang, Y., Zhang, Y., Mao, W. L., Ewing, R. C. 2019; 114 (9)

    View details for DOI 10.1063/1.5079868

    View details for Web of Science ID 000460820600017

  • Disorder in M(n+1)AX(n) phases at the atomic scale NATURE COMMUNICATIONS Wang, C., Yang, T., Tracy, C. L., Lu, C., Zhang, H., Hu, Y., Wang, L., Qi, L., Gu, L., Huang, Q., Zhang, J., Wang, J., Xue, J., Ewing, R. C., Wang, Y. 2019; 10
  • Evolution and Structure of the Scientific Basis for Nuclear Waste Management MRS ADVANCES Diaz-Maurin, F., Sun, H. C., Yu, J., Ewing, R. C. 2019; 4 (17-18): 959–64
  • Dissolution of radioactive, cesium-rich microparticles released from the Fukushima Daiichi Nuclear Power Plant in simulated lung fluid, pure-water, and seawater. Chemosphere Suetake, M. n., Nakano, Y. n., Furuki, G. n., Ikehara, R. n., Komiya, T. n., Kurihara, E. n., Morooka, K. n., Yamasaki, S. n., Ohnuki, T. n., Horie, K. n., Takehara, M. n., Law, G. T., Bower, W. n., Grambow, B. n., Ewing, R. C., Utsunomiya, S. n. 2019; 233: 633–44

    Abstract

    To understand the chemical durability of highly radioactive cesium-rich microparticles (CsMPs) released from the Fukushima Daiichi Nuclear Power Plant in March 2011, we have, for the first time, performed systematic dissolution experiments with CsMPs isolated from Fukushima soils (one sample with 108 Bq and one sample with 57.8 Bq of 137Cs) using three types of solutions: simulated lung fluid, ultrapure water, and artificial sea water, at 25 and 37 °C for 1-63 days. The 137Cs was released rapidly within three days and then steady-state dissolution was achieved for each solution type. The steady-state 137Cs release rate at 25 °C was determined to be 4.7 × 103, 1.3 × 103, and 1. 3 × 103 Bq·m-2 s-1 for simulated lung fluid, ultrapure water, and artificial sea water, respectively. This indicates that the simulated lung fluid promotes the dissolution of CsMPs. The dissolution of CsMPs is similar to that of Si-based glass and is affected by the surface moisture conditions. In addition, the Cs release from the CsMPs is constrained by the rate-limiting dissolution of silicate matrix. Based on our results, CsMPs with ∼2 Bq, which can be potentially inhaled and deposited in the alveolar region, are completely dissolved after >35 years. Further, CsMPs could remain in the environment for several decades; as such, CsMPs are important factors contributing to the long-term impacts of radioactive Cs in the environment.

    View details for DOI 10.1016/j.chemosphere.2019.05.248

    View details for PubMedID 31195267

  • Probabilistic Performance Assessment vs. the Safety Case Approach MRS ADVANCES Diaz-Maurin, F., Ewing, R. C. 2019; 4 (17-18): 987–92
  • Mission Impossible? Socio-Technical Integration of Nuclear Waste Geological Disposal Systems SUSTAINABILITY Diaz-Maurin, F., Ewing, R. C. 2018; 10 (12)

    View details for DOI 10.3390/su10124390

    View details for Web of Science ID 000455338100056

  • Grain size effects on irradiated CeO2, ThO2, and UO2 ACTA MATERIALIA Cureton, W. F., Palomares, R. I., Walters, J., Tracy, C. L., Chen, C., Ewing, R. C., Baldinozzi, G., Lian, J., Trautmann, C., Lang, M. 2018; 160: 47–56
  • A Critical Review of Existing Criteria for the Prediction of Pyrochlore Formation and Stability INORGANIC CHEMISTRY Fuentes, A. F., Montemayor, S. M., Maczka, M., Lang, M., Ewing, R. C., Amador, U. 2018; 57 (19): 12093–105

    Abstract

    Depending on intrinsic (e.g., radius ratio rule rLn/ rZr) and extrinsic factors (e.g., processing conditions), pyrochlore-type Ln2Zr2O7 oxides achieve variable degrees of structural disorder. We report on a systematic study of the structural and microstructural characteristics of the Gd2- xLn xZr2O7 system, exploring the effect of replacing Gd with a wide range of homovalent lanthanide ions (Ln = Nd, Sm, Dy, Ho, Y, and Er; x = 0.20 and 0.80). All compositions were prepared via a mechanochemical reaction between the corresponding oxides and characterized by X-ray diffraction (standard and synchrotron sources) using the Rietveld method, as well as by Raman spectroscopy. Irrespective of chemical composition, this study reveals that all compositions exhibit a fluorite-like structure. Furthermore, by firing each sample at 800 and 1400 °C, we are able to analyze the transition to pyrochlore-like structures, featuring different degrees of disorder, in all but Gd1.20Y0.80Zr2O7, which retains the fluorite structure even after heating. The structural data are used to assess the existing criteria for predicting the formation and stability of the pyrochlore structure; according to this analysis, the simple radius ratio rule ( rLn/ rZr), provides a useful and sufficiently robust criterion. Because the pyrochlore structure has a strong tendency to disorder, it is not possible to define an empirical index similar to the Goldschmidt tolerance factor for perovskite.

    View details for PubMedID 30198710

  • Isotopic signature and nano-texture of cesium-rich micro-particles: Release of uranium and fission products from the Fukushima Daiichi Nuclear Power Plant Imoto, J., Ochiai, A., Suetake, M., Ikehara, R., Horie, K., Takehara, M., Yamasaki, S., Ohnuki, T., Law, G., Grambow, B., Ewing, R., Utsunomiya, S. AMER CHEMICAL SOC. 2018
  • Uranium dioxides and debris fragments released to the environment with cesium-rich microparticles from the Fukushima Daiichi Nuclear Power Plant Utsunomiya, S., Ochiai, A., Suetake, M., Komiya, T., Yamasaki, S., Law, G., Grambow, B., Ohnuki, T., Ewing, R. AMER CHEMICAL SOC. 2018
  • Novel Method of Quantifying Radioactive Cesium-Rich Microparticles (CsMPs) in the Environment from the Fukushima Daiichi Nuclear Power Plant ENVIRONMENTAL SCIENCE & TECHNOLOGY Ikehara, R., Suetake, M., Komiya, T., Furuki, G., Ochiai, A., Yamasaki, S., Bower, W. R., Law, G. W., Ohnuki, T., Grambow, B., Ewing, R. C., Utsunomiya, S. 2018; 52 (11): 6390–98

    Abstract

    Highly radioactive cesium-rich microparticles (CsMPs) were released from the Fukushima Daiichi nuclear power plant (FDNPP) to the surrounding environment at an early stage of the nuclear disaster in March of 2011; however, the quantity of released CsMPs remains undetermined. Here, we report a novel method to quantify the number of CsMPs in surface soils at or around Fukushima and the fraction of radioactivity they contribute, which we call "quantification of CsMPs" (QCP) and is based on autoradiography. Here, photostimulated luminescence (PSL) is linearly correlated to the radioactivity of various microparticles, with a regression coefficient of 0.0523 becquerel/PSL/h (Bq/PSL/h). In soil collected from Nagadoro, Fukushima, Japan, CsMPs were detected in soil sieved with a 114 μm mesh. There was no overlap between the radioactivities of CsMPs and clay particles adsorbing Cs. Based on the distribution of radioactivity of CsMPs, the threshold radioactivity of CsMPs in the size fraction of <114 μm was determined to be 0.06 Bq. Based on this method, the number and radioactivity fraction of CsMPs in four surface soils collected from the vicinity of the FDNPP were determined to be 48-318 particles per gram and 8.53-31.8%, respectively. The QCP method is applicable to soils with a total radioactivity as high as ∼106 Bq/kg. This novel method is critically important and can be used to quantitatively understand the distribution and migration of the highly radioactive CsMPs in near-surface environments surrounding Fukushima.

    View details for PubMedID 29782160

  • Radiation-damage-induced transitions in zircon: Percolation theory applied to hardness and elastic moduli as a function of density APPLIED PHYSICS LETTERS Beirau, T., Nix, W. D., Ewing, R. C., Poellmann, H., Salje, E. H. 2018; 112 (20)

    View details for DOI 10.1063/1.5030626

    View details for Web of Science ID 000432553900019

  • Radiation-induced effects on the mechanical properties of natural ZrSiO4: double cascade-overlap damage accumulation PHYSICS AND CHEMISTRY OF MINERALS Beirau, T., Nix, W. D., Poellmann, H., Ewing, R. C. 2018; 45 (5): 435–42
  • The thermal stability and consolidation of perovskite variant Cs2SnCl6 using spark plasma sintering JOURNAL OF THE AMERICAN CERAMIC SOCIETY Scott, S. M., Zhu, W., Yao, T., Vienna, J. D., Ewing, R. C., Lian, J. 2018; 101 (5): 2060–65

    View details for DOI 10.1111/jace.15372

    View details for Web of Science ID 000426513900031

  • Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics JOURNAL OF NUCLEAR MATERIALS Tracy, C. L., Chen, C., Park, S., Davisson, M., Ewing, R. C. 2018; 502: 68–75
  • Review of recent experimental results on the behavior of actinide-bearing oxides and related materials in extreme environments PROGRESS IN NUCLEAR ENERGY Tracy, C. L., Lang, M., Zhang, F., Park, S., Palomares, R. I., Ewing, R. C. 2018; 104: 342–58
  • Radiation-induced disorder in compressed lanthanide zirconates PHYSICAL CHEMISTRY CHEMICAL PHYSICS Park, S., Tracy, C. L., Zhang, F., Park, C., Trautmann, C., Tkachev, S. N., Lang, M., Maoah, W. L., Ewing, R. C. 2018; 20 (9): 6187–97

    Abstract

    The effects of swift heavy ion irradiation-induced disordering on the behavior of lanthanide zirconate compounds (Ln2Zr2O7 where Ln = Sm, Er, or Nd) at high pressures are investigated. After irradiation with 2.2 GeV 197Au ions, the initial ordered pyrochlore structure (Fd3[combining macron]m) transformed to a defect-fluorite structure (Fm3[combining macron]m) in Sm2Zr2O7 and Nd2Zr2O7. For irradiated Er2Zr2O7, which has a defect-fluorite structure, ion irradiation induces local disordering by introducing Frenkel defects despite retention of the initial structure. When subjected to high pressures (>29 GPa) in the absence of irradiation, all of these compounds transform to a cotunnite-like (Pnma) phase, followed by sluggish amorphization with further compression. However, if these compounds are irradiated prior to compression, the high pressure cotunnite-like phase is not formed. Rather, they transform directly from their post-irradiation defect-fluorite structure to an amorphous structure upon compression (>25 GPa). Defects and disordering induced by swift heavy ion irradiation alter the transformation pathways by raising the energetic barriers for the transformation to the high pressure cotunnite-like phase, rendering it inaccessible. As a result, the high pressure stability field of the amorphous phase is expanded to lower pressures when irradiation is coupled with compression. The responses of materials in the lanthanide zirconate system to irradiation and compression, both individually and in tandem, are strongly influenced by the specific lanthanide composition, which governs the defect energetics at extreme conditions.

    View details for PubMedID 29431823

  • Uranium Dioxides and Debris Fragments Released to the Environment with Cesium-Rich Microparticles from the Fukushima Daiichi Nuclear Power Plant ENVIRONMENTAL SCIENCE & TECHNOLOGY Ochiai, A., Imoto, J., Suetake, M., Komiya, T., Furuki, G., Ikehara, R., Yamasaki, S., Law, G. W., Ohnuki, T., Grambow, B., Ewing, R. C., Utsunomiya, S. 2018; 52 (5): 2586–94

    Abstract

    Trace U was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) during the meltdowns, but the speciation of the released components of the nuclear fuel remains unknown. We report, for the first time, the atomic-scale characteristics of nanofragments of the nuclear fuels that were released from the FDNPP into the environment. Nanofragments of an intrinsic U-phase were discovered to be closely associated with radioactive cesium-rich microparticles (CsMPs) in paddy soils collected ∼4 km from the FDNPP. The nanoscale fuel fragments were either encapsulated by or attached to CsMPs and occurred in two different forms: (i) UO2+X nanocrystals of ∼70 nm size, which are embedded into magnetite associated with Tc and Mo on the surface and (ii) Isometric (U,Zr)O2+X nanocrystals of ∼200 nm size, with the U/(U+Zr) molar ratio ranging from 0.14 to 0.91, with intrinsic pores (∼6 nm), indicating the entrapment of vapors or fission-product gases during crystallization. These results document the heterogeneous physical and chemical properties of debris at the nanoscale, which is a mixture of melted fuel and reactor materials, reflecting the complex thermal processes within the FDNPP reactor during meltdown. Still CsMPs are an important medium for the transport of debris fragments into the environment in a respirable form.

    View details for PubMedID 29378406

  • A(2)TiO(5) (A = Dy, Gd, Er, Yb) at High Pressure INORGANIC CHEMISTRY Park, S., Rittman, D. R., Tracy, C. L., Chapman, K. W., Zhang, F., Park, C., Tkachev, S. N., O'Quinn, E., Shamblin, J., Lang, M., Mao, W. L., Ewing, R. C. 2018; 57 (4): 2269–77

    Abstract

    The structural evolution of lanthanide A2TiO5 (A = Dy, Gd, Yb, Er) at high pressure is investigated using synchrotron X-ray diffraction. The effects of A-site cation size and of the initial structure are systematically examined by varying the composition of the isostructural lanthanide titanates and the structure of dysprosium titanate polymorphs (orthorhombic, hexagonal, and cubic), respectively. All samples undergo irreversible high-pressure phase transformations, but with different onset pressures depending on the initial structure. While each individual phase exhibits different phase transformation histories, all samples commonly experience a sluggish transformation to a defect cotunnite-like (Pnma) phase for a certain pressure range. Orthorhombic Dy2TiO5 and Gd2TiO5 form P21am at pressures below 9 GPa and Pnma above 13 GPa. Pyrochlore-type Dy2TiO5 and Er2TiO5 as well as defect-fluorite-type Yb2TiO5 form Pnma at ∼21 GPa, followed by Im3̅m. Hexagonal Dy2TiO5 forms Pnma directly, although a small amount of remnants of hexagonal Dy2TiO5 is observed even at the highest pressure (∼55 GPa) reached, indicating kinetic limitations in the hexagonal Dy2TiO5 phase transformations at high pressure. Decompression of these materials leads to different metastable phases. Most interestingly, a high-pressure cubic X-type phase (Im3̅m) is confirmed using high-resolution transmission electron microscopy on recovered pyrochlore-type Er2TiO5. The kinetic constraints on this metastable phase yield a mixture of both the X-type phase and amorphous domains upon pressure release. This is the first observation of an X-type phase for an A2BO5 composition at high pressure.

    View details for PubMedID 29420026

  • Initial stages of ion beam-induced phase transformations in Gd2O3 and Lu2O3 APPLIED PHYSICS LETTERS Chen, C., Tracy, C. L., Wang, C., Lang, M., Ewing, R. C. 2018; 112 (7)

    View details for DOI 10.1063/1.5013018

    View details for Web of Science ID 000425493600051

  • Swift-heavy ion irradiation response and annealing behavior of A(2)TiO(5) (A = Nd, Gd, and Yb) JOURNAL OF SOLID STATE CHEMISTRY Park, S., Tracy, C. L., Zhang, F., Palomares, R. I., Park, C., Trautmann, C., Lang, M., Mao, W. L., Ewing, R. C. 2018; 258: 108–16
  • Role of the X and n factors in ion-irradiation induced phase transformations of M(n+1)AX(n) phases ACTA MATERIALIA Wang, C., Yang, T., Tracy, C. L., Xiao, J., Liu, S., Fang, Y., Yan, Z., Ge, W., Xue, J., Zhang, J., Wang, J., Huang, Q., Ewing, R. C., Wang, Y. 2018; 144: 432–46
  • Similar local order in disordered fluorite and aperiodic pyrochlore structures ACTA MATERIALIA Shamblin, J., Tracy, C. L., Palomares, R. I., O'Quinn, E. C., Ewing, R. C., Neuefeind, J., Feygenson, M., Behrens, J., Trautmann, C., Lang, M. 2018; 144: 60–67
  • Phase transformation pathways of ultrafast-laser-irradiated Ln(2)O(3) (Ln = Er-Lu) PHYSICAL REVIEW B Rittman, D. R., Tracy, C. L., Chen, C., Solomon, J. M., Asta, M., Mao, W. L., Yalisove, S. M., Ewing, R. C. 2018; 97 (2)
  • Lanthanide stannate pyrochlores (Ln(2)Sn(2)O(7); Ln = Nd, Gd, Er) at high pressure JOURNAL OF PHYSICS-CONDENSED MATTER Turner, K. M., Tracy, C. L., Mao, W. L., Ewing, R. C. 2017; 29 (50)
  • Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln  =  Nd, Gd, Er) at high pressure. Journal of physics. Condensed matter : an Institute of Physics journal Turner, K. M., Tracy, C. L., Mao, W. L., Ewing, R. C. 2017; 29 (50): 504005

    Abstract

    Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln  =  Nd, Gd, and Er) were investigated in situ to 50 GPa in order to determine their structural response to compression and compare their response to that of lanthanide titanate, zirconate, and hafnate pyrochlores. The cation radius ratio of A3+/B4+ in pyrochlore oxides (A2B2O7) is thought to be the dominant feature that influences their response on compression. The ionic radius of Sn4+ is intermediate to that of Ti4+, Zr4+, and Hf4+, but the 〈Sn-O〉 bond in stannate pyrochlore is more covalent than the 〈B-O〉 bonds in titanates, zirconate, and hafnates. In stannates, based on in situ Raman spectroscopy, pyrochlore cation and anion sublattices begin to disorder with the onset of compression, first measured at 0.3 GPa. The extent of sublattice disorder versus pressure is greater in stannates with a smaller Ln3+ cation. Stannate pyrochlores (Fd-3m) begin a sluggish transformation to an orthorhombic, cotunnite-like structure at ~28 GPa; similar transitions have been observed in titanate, zirconate, and hafnate pyrochlores at varying pressures (18-40 GPa) with cation radius ratio. The extent of the phase transition versus pressure varies directly with the size of the Ln3+ cation. Post-decompression from ~50 GPa, Er2Sn2O7 and Gd2Sn2O7 adopt a pyrochlore structure, rather than the multi-scale defect-fluorite  +  weberite-type structure adopted by Nd2Sn2O7 that is characteristic of titanate, zirconate, and hafnate pyrochlores under similar conditions. Like pyrochlore titanates, zirconates, and hafnates, the bulk modulus, B 0, of stannates varies linearly and inversely with cation radius ratio from 1 1 1 GPa (Nd2Sn2O7) to 251 GPa (Er2Sn2O7). The trends of bulk moduli in stannates in this study are in excellent agreement with previous experimental studies on stannates and suggest that the size of the Ln3+ cation is the primary determining factor of B 0. Additionally, when normalized to r A/r B, the bulk moduli of stannates are comparable to those of zirconates and hafnates, which vary from titanates. Our results suggest that the cation radius ratio strongly influences the bulk moduli of stannates, as well as their overall compression response.

    View details for DOI 10.1088/1361-648X/aa9960

    View details for PubMedID 29176046

  • Gauging the risk from nuclear waste NATURE Ewing, R. C. 2017; 552 (7683): 31

    View details for Web of Science ID 000417560500030

    View details for PubMedID 29219986

  • Lanthanide stannate pyrochlores (Ln<sub>2</sub>Sn<sub>2</sub>O<sub>7</sub>; Ln = Nd, Gd, Er) at high pressure. Journal of physics. Condensed matter : an Institute of Physics journal Turner, K. M., Tracy, C. L., Mao, W. L., Ewing, R. C. 2017

    Abstract

    Lanthanide stannate pyrochlores (Ln2Sn2O7; Ln=Nd, Gd, and Er) were investigated in situ to 50 GPa in order to determine their structural response to compression and compare it to that of lanthanide titanate, zirconate, and hafnate pyrochlores. The cation radius ratio of A3+/B4+ in pyrochlore oxides (A2B2O7) is thought to be the dominant property that influences their compression response. The ionic radius of Sn4+ is intermediate to that of Ti4+, Zr4+, and Hf4+, but the <Sn-O> bond in stannate pyrochlore is more covalent than the <B-O> bonds in titanates, zirconate, and hafnates. In stannates, the pyrochlore cation and anion sublattices begin to disorder at 0.3 GPa. The extent of sublattice disorder vs. pressure is greater in stannates with a smaller Ln3+ cation. Stannate pyrochlores (Fd-3m) begin a sluggish transformation to a cotunnite-like structure (Pnma) at ~28 GPa; similar transitions have been observed in titanate, zirconate, and hafnate pyrochlore at varying pressures with cation radius ratio. The extent of the phase transition vs. pressure varies directly with the size of the Ln3+ cation. Post-decompression from ~50 GPa, Er2Sn2O7 and Gd2Sn2O7 adopt a pyrochlore structure, rather than the multiscale defect-fluorite + weberite structure adopted by Nd2Sn2O7 that is characteristic of titanate, zirconate, and hafnate pyrochlore treated to similar conditions. Like pyrochlore titanates, zirconates, and hafnates, the bulk modulus, B0, of stannates varies linearly and inversely with cation radius ratio. The trends of bulk moduli in stannates in this study are in excellent agreement with previous experimental studies on stannates, and suggest that the size of the Ln3+ cation is a primary determining factor of B0. Additionally, when normalized to rA/rB, the bulk moduli of stannates are comparable to those of zirconates and hafnates, which vary from titanates. Our results suggest that the cation radius ratio strongly influences the bulk moduli of stannates as well as their overall compression response.

    View details for DOI 10.1088/1361-648X/aa9960

    View details for PubMedID 29120343

  • In situ TEM observation of alpha-particle induced annealing of radiation damage in Durango apatite SCIENTIFIC REPORTS Li, W., Shen, Y., Zhou, Y., Nan, S., Chen, C., Ewing, R. C. 2017; 7: 14108

    Abstract

    A major issue in thermochronology and U-Th-Pb dating is the effect of radiation damage, created by α-recoils from α-decay events, on the diffusion of radiogenic elements (e.g., He and Pb) in host mineral. Up until now, thermal events have been considered as the only source of energy for the recovery of radiation-damage. However, irradiation, such as from the α-particle of the α-decay event, can itself induce damage recovery. Quantification of radiation-induced recovery caused by α-particles during α-decay events has not been possible, as the recovery process at the atomic-scale has been difficult to observe. Here we present details of the dynamics of the amorphous-to-crystalline transition process during α-particle irradiations using in situ transmission electron microscopy (TEM) and consecutive ion-irradiations: 1 MeV Kr2+ (simulating α-recoil damage), followed by 400 keV He+ (simulating α-particle annealing). Upon the He+ irradiation, partial recrystallization of the original, fully-amorphous Durango apatite was clearly evident and quantified based on the gradual appearance of new crystalline domains in TEM images and new diffraction maxima in selected area electron diffraction patterns. Thus, α-particle induced annealing occurs and must be considered in models of α-decay event damage and its effect on the diffusion of radiogenic elements in geochronology and thermochronology.

    View details for PubMedID 29074979

  • Radioactive waste forms for the future Ewing, R. AMER CHEMICAL SOC. 2017
  • Inversion in Mg1-xNixAl2O4 Spinel: New Insight into Local Structure. Journal of the American Chemical Society O'Quinn, E. C., Shamblin, J., Perlov, B., Ewing, R. C., Neuefeind, J., Feygenson, M., Gussev, I., Lang, M. 2017; 139 (30): 10395-10402

    Abstract

    A wide variety of compositions adopt the isometric spinel structure (AB2O4), in which the atomic-scale ordering is conventionally described according to only three structural degrees of freedom. One, the inversion parameter, is traditionally defined as the degree of cation exchange between the A- and B-sites. This exchange, a measure of intrinsic disorder, is fundamental to understanding the variation in the physical properties of different spinel compositions. Based on neutron total scattering experiments, we have determined that the local structure of Mg1-xNixAl2O4 spinel cannot be understood as simply being due to cation disorder. Rather, cation inversion creates a local tetragonal symmetry that extends over sub-nanometer domains. Consequently, the simple spinel structure is more complicated than previously thought, as more than three parameters are needed to fully describe the structure. This new insight provides a framework by which the behavior of spinel can be more accurately modeled under the extreme environments important for many geophysics and energy-related applications, including prediction of deep seismic activity and immobilization of nuclear waste in oxides.

    View details for DOI 10.1021/jacs.7b04370

    View details for PubMedID 28683545

  • Isotopic signature and nano-texture of cesium-rich micro-particles: Release of uranium and fission products from the Fukushima Daiichi Nuclear Power Plant. Scientific reports Imoto, J., Ochiai, A., Furuki, G., Suetake, M., Ikehara, R., Horie, K., Takehara, M., Yamasaki, S., Nanba, K., Ohnuki, T., Law, G. T., Grambow, B., Ewing, R. C., Utsunomiya, S. 2017; 7 (1): 5409

    Abstract

    Highly radioactive cesium-rich microparticles (CsMPs) released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) provide nano-scale chemical fingerprints of the 2011 tragedy. U, Cs, Ba, Rb, K, and Ca isotopic ratios were determined on three CsMPs (3.79-780 Bq) collected within ~10 km from the FDNPP to determine the CsMPs' origin and mechanism of formation. Apart from crystalline Fe-pollucite, CsFeSi2O6 · nH2O, CsMPs are comprised mainly of Zn-Fe-oxide nanoparticles in a SiO2 glass matrix (up to ~30 wt% of Cs and ~1 wt% of U mainly associated with Zn-Fe-oxide). The 235U/238U values in two CsMPs: 0.030 (±0.005) and 0.029 (±0.003), are consistent with that of enriched nuclear fuel. The values are higher than the average burnup estimated by the ORIGEN code and lower than non-irradiated fuel, suggesting non-uniform volatilization of U from melted fuels with different levels of burnup, followed by sorption onto Zn-Fe-oxides. The nano-scale texture and isotopic analyses provide a partial record of the chemical reactions that occurred in the fuel during meltdown. Also, the CsMPs were an important medium of transport for the released radionuclides in a respirable form.

    View details for DOI 10.1038/s41598-017-05910-z

    View details for PubMedID 28710475

    View details for PubMedCentralID PMC5511200

  • Defect accumulation in swift heavy ion-irradiated CeO2 and ThO2 JOURNAL OF MATERIALS CHEMISTRY A Palomares, R. I., Shamblin, J., Tracy, C. L., Neuefeind, J., Ewing, R. C., Trautmann, C., Lang, M. 2017; 5 (24): 12193–201

    View details for DOI 10.1039/c7ta02640d

    View details for Web of Science ID 000403664800026

  • Pressure-induced structural modifications of rare-earth hafnate pyrochlore. Journal of physics. Condensed matter : an Institute of Physics journal Turner, K. M., Rittman, D. R., Heymach, R. A., Tracy, C. L., Turner, M. L., Fuentes, A. F., Mao, W. L., Ewing, R. C. 2017; 29 (25): 255401-?

    Abstract

    Complex oxides with the pyrochlore (A2B2O7) and defect-fluorite ((A,B)4O7) structure-types undergo structural transformations under high-pressure. Rare-earth hafnates (A2Hf2O7) form the pyrochlore structure for A  =  La-Tb and the defect-fluorite structure for A  =  Dy-Lu. High-pressure transformations in A2Hf2O7 pyrochlore (A  =  Sm, Eu, Gd) and defect-fluorite (A  =  Dy, Y, Yb) were investigated up to ~50 GPa and characterized by in situ Raman spectroscopy and synchrotron x-ray diffraction (XRD). Raman spectra at ambient pressure revealed that all compositions, including the defect-fluorites, have some pyrochlore-type short-range order. In situ high-pressure synchrotron XRD showed that all of the rare earth hafnates investigated undergo a pressure-induced phase transition to a cotunnite-like (orthorhombic) structure that begins between 18 and 25 GPa. The phase transition to the cotunnite-like structure is not complete at 50 GPa, and upon release of pressure, the hafnates transform to defect-fluorite with an amorphous component. For all compositions, in situ Raman spectroscopy showed that disordering occurs gradually with increasing pressure. Pyrochlore-structured hafnates retain their short-range order to a higher pressure (30 GPa vs.  <10 GPa) than defect-fluorite-structured hafnates. Rare earth hafnates quenched from 50 GPa show Raman spectra consistent with weberite-type structures, as also reported for irradiated rare-earth stannates. The second-order Birch-Murnaghan equation of state fit gives a bulk modulus of ~250 GPa for hafnates with the pyrochlore structure, and ~400 GPa for hafnates with the defect-fluorite structure. Dy2Hf2O7 is intermediate in its response, with some pyrochlore-type ordering, based on Raman spectroscopy and the equation of state, with a bulk modulus of ~300 GPa. As predicted based on the similar ionic radius of Zr(4+) and Hf(4+), rare-earth hafnates show similar behavior to that reported for rare earth zirconates at high pressure.

    View details for DOI 10.1088/1361-648X/aa7148

    View details for PubMedID 28541929

  • Minerals: A rescue package for imperilled collection. Nature Bornhorst, T. J., Poulsen, C. J., Ewing, R. C. 2017; 546 (7657): 210

    View details for DOI 10.1038/546210b

    View details for PubMedID 28593962

  • High pressure synthesis of a hexagonal close-packed phase of the high-entropy alloy CrMnFeCoNi NATURE COMMUNICATIONS Tracy, C. L., Park, S., Rittman, D. R., Zinkle, S. J., Bei, H., Lang, M., Ewing, R. C., Mao, W. L. 2017; 8

    Abstract

    High-entropy alloys, near-equiatomic solid solutions of five or more elements, represent a new strategy for the design of materials with properties superior to those of conventional alloys. However, their phase space remains constrained, with transition metal high-entropy alloys exhibiting only face- or body-centered cubic structures. Here, we report the high-pressure synthesis of a hexagonal close-packed phase of the prototypical high-entropy alloy CrMnFeCoNi. This martensitic transformation begins at 14 GPa and is attributed to suppression of the local magnetic moments, destabilizing the initial fcc structure. Similar to fcc-to-hcp transformations in Al and the noble gases, the transformation is sluggish, occurring over a range of >40 GPa. However, the behaviour of CrMnFeCoNi is unique in that the hcp phase is retained following decompression to ambient pressure, yielding metastable fcc-hcp mixtures. This demonstrates a means of tuning the structures and properties of high-entropy alloys in a manner not achievable by conventional processing techniques.

    View details for DOI 10.1038/ncomms15634

    View details for Web of Science ID 000401966000001

    View details for PubMedID 28541277

  • Strain engineered pyrochlore at high pressure. Scientific reports Rittman, D. R., Turner, K. M., Park, S., Fuentes, A. F., Park, C., Ewing, R. C., Mao, W. L. 2017; 7 (1): 2236-?

    Abstract

    Strain engineering is a promising method for next-generation materials processing techniques. Here, we use mechanical milling and annealing followed by compression in diamond anvil cell to tailor the intrinsic and extrinsic strain in pyrochlore, Dy2Ti2O7 and Dy2Zr2O7. Raman spectroscopy, X-ray pair distribution function analysis, and X-ray diffraction were used to characterize atomic order over short-, medium-, and long-range spatial scales, respectively, under ambient conditions. Raman spectroscopy and X-ray diffraction were further employed to interrogate the material in situ at high pressure. High-pressure behavior is found to depend on the species and concentration of defects in the sample at ambient conditions. Overall, we show that defects can be engineered to lower the phase transformation onset pressure by ~50% in the ordered pyrochlore Dy2Ti2O7, and lower the phase transformation completion pressure by ~20% in the disordered pyrochlore Dy2Zr2O7. These improvements are achieved without significantly sacrificing mechanical integrity, as characterized by bulk modulus.

    View details for DOI 10.1038/s41598-017-02637-9

    View details for PubMedID 28533513

  • Ion-irradiation-induced structural evolution in Ti4AlN3 SCRIPTA MATERIALIA Wang, C., Yang, T., Chen, C., Park, S., Liu, S., Fang, Y., Yan, Z., Xue, J., Zhang, J., Wang, J., Ewing, R. C., Wang, Y. 2017; 133: 19-23
  • Photothermal effect on Fe3O4 nanoparticles irradiated by white-light for energy-efficient window applications SOLAR ENERGY MATERIALS AND SOLAR CELLS Zhao, Y., Sadat, M. E., Dunn, A., Xu, H., Chen, C., Nakasuga, W., Ewing, R. C., Shi, D. 2017; 161: 247-254
  • Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant SCIENTIFIC REPORTS Furuki, G., Imoto, J., Ochiai, A., Yamasaki, S., Nanba, K., Ohnuki, T., Grambow, B., Ewing, R. C., Utsunomiya, S. 2017; 7

    Abstract

    The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0-3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn-Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1-19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn-Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP.

    View details for DOI 10.1038/srep42731

    View details for Web of Science ID 000394294400001

    View details for PubMedID 28198440

  • Thermal annealing of natural, radiation-damaged pyrochlore ZEITSCHRIFT FUR KRISTALLOGRAPHIE-CRYSTALLINE MATERIALS Zietlow, P., Beirau, T., Mihailova, B., Groat, L. A., Chudy, T., Shelyug, A., Navrotsky, A., Ewing, R. C., Schlueter, J., Skoda, R., Bismayer, U. 2017; 232 (1-3): 25-38
  • High-pressure behavior of A(2)B(2)O(7) pyrochlore (A=Eu, Dy; B=Ti, Zr) JOURNAL OF APPLIED PHYSICS Rittman, D. R., Turner, K. M., Park, S., Fuentes, A. F., Yan, J., Ewing, R. C., Mao, W. L. 2017; 121 (4)

    View details for DOI 10.1063/1.4974871

    View details for Web of Science ID 000393480100066

  • Biomarkerless targeting and photothermal cancer cell killing by surface-electrically-charged superparamagnetic Fe3O4 composite nanoparticles. Nanoscale Han, X., Deng, Z., Yang, Z., Wang, Y., Zhu, H., Chen, B., Cui, Z., Ewing, R. C., Shi, D. 2017; 9 (4): 1457-1465

    Abstract

    A major challenge in cancer therapy is localized targeting of cancer cells for maximum therapeutic effectiveness. However, due to cancer heterogeneities, the biomarkers are either not readily available or specific for effective targeting of cancer cells. The key, therefore, is to develop a new targeting strategy that does not rely on biomarkers. A general hallmark of cancer cells is the much increased level of glycolysis. The loss of highly mobile lactate from the cytoplasm inevitably removes labile inorganic cations to form lactate salts and acids as part of the lactate cycle, creating a net of negative surface charges. This net of negative charges on cancer cell surfaces biophysically distinguishes themselves from normal cells. In this study, cancer cells are targeted by using positively-charged, fluorescent, superparamagnetic Fe3O4-composite nanoparticles. The positively-charged Fe3O4 composite nanoparticles bind predominantly to cancer cells due to their negatively-charged surfaces. Upon electrical-charge-mediated Fe3O4 nanoparticle binding onto cancer cells, irradiation by using an 808 nm laser is subsequently applied to induce photothermal hyperthermia that kills the cancer cells directly. The negatively-charged composite nanoparticles are found, however, not to target and bind the cancer cells due to the electrostatic repulsive force between them. This unique strategy paves a new path for effective targeting and direct cancer cell killing without relying on any biomarkers and anticancer drugs.

    View details for DOI 10.1039/c6nr07161a

    View details for PubMedID 27942661

  • Biomarkerless targeting and photothermal cancer cell killing by surface-electrically-charged superparamagnetic Fe3O4 composite nanoparticles NANOSCALE Han, X., Deng, Z., Yang, Z., Wang, Y., Zhu, H., Chen, B., Cui, Z., Ewing, R. C., Shi, D. 2017; 9 (4): 1457-1465

    Abstract

    A major challenge in cancer therapy is localized targeting of cancer cells for maximum therapeutic effectiveness. However, due to cancer heterogeneities, the biomarkers are either not readily available or specific for effective targeting of cancer cells. The key, therefore, is to develop a new targeting strategy that does not rely on biomarkers. A general hallmark of cancer cells is the much increased level of glycolysis. The loss of highly mobile lactate from the cytoplasm inevitably removes labile inorganic cations to form lactate salts and acids as part of the lactate cycle, creating a net of negative surface charges. This net of negative charges on cancer cell surfaces biophysically distinguishes themselves from normal cells. In this study, cancer cells are targeted by using positively-charged, fluorescent, superparamagnetic Fe3O4-composite nanoparticles. The positively-charged Fe3O4 composite nanoparticles bind predominantly to cancer cells due to their negatively-charged surfaces. Upon electrical-charge-mediated Fe3O4 nanoparticle binding onto cancer cells, irradiation by using an 808 nm laser is subsequently applied to induce photothermal hyperthermia that kills the cancer cells directly. The negatively-charged composite nanoparticles are found, however, not to target and bind the cancer cells due to the electrostatic repulsive force between them. This unique strategy paves a new path for effective targeting and direct cancer cell killing without relying on any biomarkers and anticancer drugs.

    View details for DOI 10.1039/c6nr07161a

    View details for Web of Science ID 000395422800013

  • In-vitro depth-dependent hyperthermia of human mammary gland adenocarcinoma MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS Dunn, A. W., Zhang, Y., Mast, D., Pauletti, G. M., Xu, H., Zhang, J., Ewing, R. C., Shi, D. 2016; 69: 12-16

    Abstract

    Nanoparticle mediated photothermal ablation of cancerous tissue shows promising results and applicability as a highly efficacious treatment method. As a majority of the photothermal work has been conducted with minimal attenuation of the laser before reaching the nanoparticles within surface seeded tumors in-vivo or through buffered media in-vitro, it is important to understand the effects of greater laser attenuation on photothermal efficacy mediated by changes in the scattering and absorption of the laser. Photothermal efficacy using a near infrared (NIR) 785nm laser irradiating polystyrene (PS) stabilized magnetite (Fe3O4) nanoparticles (PS-Fe3O4) is examined on MDA-MB-231 human mammary gland adenocarcinoma in-vitro. Agarose gel columns of various heights were created to simulate soft tissue and subsequently used for NIR laser attenuation. Polystyrene was found to significantly improve magnetite nanoparticle stability in serum containing media and modified Hank's Balanced Salt Solution and was able to induce significant hyperthermic ablation at mass concentrations which also did not elicit significant innate toxicity. Furthermore it was found that the polystyrene coating significantly reduced innate toxicity over 48h compared to uncoated magnetite. Agar gel layers provided similar optical attenuation in the NIR region to skin and prostate.

    View details for DOI 10.1016/j.msec.2016.06.026

    View details for Web of Science ID 000383930900002

    View details for PubMedID 27612683

  • Energetics of a Uranothorite (Th1-xUxSiO4) Solid Solution CHEMISTRY OF MATERIALS Guo, X., Szenknect, S., Mesbah, A., Clavier, N., Poinssot, C., Wu, D., Xu, H., Dacheux, N., Ewing, R. C., Navrotsky, A. 2016; 28 (19): 7117-7124
  • Anisotropic mechanical properties of zircon and the effect of radiation damage PHYSICS AND CHEMISTRY OF MINERALS Beirau, T., Nix, W. D., Bismayer, U., Boatner, L. A., Isaacson, S. G., Ewing, R. C. 2016; 43 (9): 627-638
  • Structural response of titanate pyrochlores to swift heavy ion irradiation ACTA MATERIALIA Shamblin, J., Tracy, C. L., Ewing, R. C., Zhang, F., Li, W., Trautmann, C., Lang, M. 2016; 117: 207-215
  • Role of composition, bond covalency, and short-range order in the disordering of stannate pyrochlores by swift heavy ion irradiation PHYSICAL REVIEW B Tracy, C. L., Shamblin, J., Park, S., Zhang, F., Trautmann, C., Lang, M., Ewing, R. C. 2016; 94 (6)
  • Geological Disposal of Nuclear Waste: a Primer ELEMENTS Ewing, R. C., Whittleston, R. A., Yardley, B. W. 2016; 12 (4): 233-237
  • Stability of fluorite-type La2Ce2O7 under extreme conditions JOURNAL OF ALLOYS AND COMPOUNDS Zhang, F. X., Tracy, C. L., Lang, M., Ewing, R. C. 2016; 674: 168-173
  • First experimental determination of the solubility constant of coffinite GEOCHIMICA ET COSMOCHIMICA ACTA Szenknect, S., Mesbah, A., Cordara, T., Clavier, N., Brau, H., Le Goff, X., Poinssot, C., Ewing, R. C., Dacheux, N. 2016; 181: 36-53
  • Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant SCIENCE OF THE TOTAL ENVIRONMENT Yamasaki, S., Imoto, J., Furuki, G., Ochiai, A., Ohnuki, T., Sueki, K., Nanba, K., Ewing, R. C., Utsunomiya, S. 2016; 551: 155-162
  • Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant. The Science of the total environment Yamasaki, S., Imoto, J., Furuki, G., Ochiai, A., Ohnuki, T., Sueki, K., Nanba, K., Ewing, R. C., Utsunomiya, S. 2016; 551-552: 155-62

    Abstract

    The migration and dispersion of radioactive Cs (mainly (134)Cs and (137)Cs) are of critical concern in the area surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP). Considerable uncertainty remains in understanding the properties and dynamics of radioactive Cs transport by surface water, particularly during rainfall-induced flood events to the ocean. Physical and chemical properties of unique estuary sediments, collected from the Kuma River, 4.0km south of the FDNPP, were quantified in this study. These were deposited after storm events and now occur as dried platy sediments on beach sand. The platy sediments exhibit median particle sizes ranging from 28 to 32μm. There is increasing radioactivity towards the bottom of the layers deposited; approximately 28 and 38Bqg(-1) in the upper and lower layers, respectively. The difference in the radioactivity is attributed to a larger number of particles associated with radioactive Cs in the lower part of the section, suggesting that radioactive Cs in the suspended soils transported by surface water has decreased over time. Sequential chemical extractions showed that ~90% of (137)Cs was strongly bound to the residual fraction in the estuary samples, whereas 60~80% of (137)Cs was bound to clays in the six paddy soils. This high concentration in the residual fraction facilitates ease of transport of clay and silt size particles through the river system. Estuary sediments consist of particles <100μm. Radioactive Cs desorption experiments using the estuary samples in artificial seawater revealed that 3.4±0.6% of (137)Cs was desorbed within 8h. More than 96% of (137)Cs remained strongly bound to clays. Hence, particle size is a key factor that determines the travel time and distance during the dispersion of (137)Cs in the ocean.

    View details for DOI 10.1016/j.scitotenv.2016.01.155

    View details for PubMedID 26874771

  • Probing disorder in isometric pyrochlore and related complex oxides NATURE MATERIALS Shamblin, J., Feygenson, M., Neuefeind, J., Tracy, C. L., Zhang, F., Finkeldei, S., Bosbach, D., Zhou, H., Ewing, R. C., Lang, M. 2016; 15 (5): 507-?

    Abstract

    There has been an increased focus on understanding the energetics of structures with unconventional ordering (for example, correlated disorder that is heterogeneous across different length scales). In particular, compounds with the isometric pyrochlore structure, A2B2O7, can adopt a disordered, isometric fluorite-type structure, (A, B)4O7, under extreme conditions. Despite the importance of the disordering process there exists only a limited understanding of the role of local ordering on the energy landscape. We have used neutron total scattering to show that disordered fluorite (induced intrinsically by composition/stoichiometry or at far-from-equilibrium conditions produced by high-energy radiation) consists of a local orthorhombic structural unit that is repeated by a pseudo-translational symmetry, such that orthorhombic and isometric arrays coexist at different length scales. We also show that inversion in isometric spinel occurs by a similar process. This insight provides a new basis for understanding order-to-disorder transformations important for applications such as plutonium immobilization, fast ion conduction, and thermal barrier coatings.

    View details for DOI 10.1038/NMAT4581

    View details for Web of Science ID 000374763500010

    View details for PubMedID 26928636

  • Anisotropic expansion and amorphization of Ga2O3 irradiated with 946 MeV Au ions NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Tracy, C. L., Lang, M., Severin, D., Bender, M., Trautmann, C., Ewing, R. C. 2016; 374: 40-44
  • Phase transition and water incorporation into Eu2Sn2O7 pyrochlore at high pressure CHEMICAL PHYSICS LETTERS Zhang, F. X., Lang, M., Ewing, R. C. 2016; 650: 138-143
  • Reassess New Mexico's nuclear-waste repository NATURE Tracy, C. L., Dustin, M. K., Ewing, R. C. 2016; 529 (7585): 149-151

    View details for Web of Science ID 000368015700013

    View details for PubMedID 26762442

  • Mechanical properties of natural radiation-damaged titanite and temperature-induced structural reorganization: A nanoindentation and Raman spectroscopic study AMERICAN MINERALOGIST Beirau, T., Nix, W. D., Ewing, R. C., Schneider, G. A., Groats, L. A., Bismayer, U. 2016; 101 (1-2): 399-406
  • Targeting Negative Surface Charges of Cancer Cells by Multifunctional Nanoprobes. Theranostics Chen, B., Le, W., Wang, Y., Li, Z., Wang, D., Ren, L., Lin, L., Cui, S., Hu, J. J., Hu, Y., Yang, P., Ewing, R. C., Shi, D., Cui, Z. 2016; 6 (11): 1887-1898

    Abstract

    A set of electrostatically charged, fluorescent, and superparamagnetic nanoprobes was developed for targeting cancer cells without using any molecular biomarkers. The surface electrostatic properties of the established cancer cell lines and primary normal cells were characterized by using these nanoprobes with various electrostatic signs and amplitudes. All twenty two randomly selected cancer cell lines of different organs, but not normal control cells, bound specifically to the positively charged nanoprobes. The relative surface charges of cancer cells could be quantified by the percentage of cells captured magnetically. The activities of glucose metabolism had a profound impact on the surface charge level of cancer cells. The data indicate that an elevated glycolysis in the cancer cells led to a higher level secretion of lactate. The secreted lactate anions are known to remove the positive ions, leaving behind the negative changes on the cell surfaces. This unique metabolic behavior is responsible for generating negative cancer surface charges in a perpetuating fashion. The metabolically active cancer cells are shown to a unique surface electrostatic pattern that can be used for recovering cancer cells from the circulating blood and other solutions.

    View details for DOI 10.7150/thno.16358

    View details for PubMedID 27570558

    View details for PubMedCentralID PMC4997244

  • Pressure-induced phase transitions of beta-type pyrochlore CsTaWO6 RSC ADVANCES Zhang, F. X., Tracy, C. L., Shamblin, J., Palomares, R. I., Lang, M., Park, S., PARK, C., Tkachev, S., Ewing, R. C. 2016; 6 (97): 94287-94293

    View details for DOI 10.1039/c6ra11185h

    View details for Web of Science ID 000385632400001

  • Study on structural recovery of graphite irradiated with swift heavy ions at high temperature NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Pellemoine, F., Avilov, M., Bender, M., Ewing, R. C., Fernandes, S., Lang, M., Li, W. X., MITTIG, W., Schein, M., Severin, D., Tomut, M., Trautmann, C., Zhang, F. X. 2015; 235: 522-524
  • Phase transformations in Ln(2)O(3) materials irradiated with swift heavy ions PHYSICAL REVIEW B Tracy, C. L., Lang, M., Zhang, F., Trautmann, C., Ewing, R. C. 2015; 92 (17)
  • Radiation Stability of Spark-Plasma-Sintered Lead Vanadate Iodoapatite JOURNAL OF THE AMERICAN CERAMIC SOCIETY Lu, F., Yao, T., Danon, Y., Zhou, J., Ewing, R. C., Lian, J. 2015; 98 (10): 3361-3366

    View details for DOI 10.1111/jace.13738

    View details for Web of Science ID 000362599000054

  • C-60 and U ion irradiation of Gd2TixZr2-xO7 pyrochlore JOURNAL OF MATERIALS RESEARCH Zhang, J., Toulemonde, M., Lang, M., Costantini, J. M., Della-Negra, S., Ewing, R. C. 2015; 30 (16): 2456-2466
  • Coffinite, USiO4, Is Abundant in Nature: So Why Is It So Difficult To Synthesize? INORGANIC CHEMISTRY Mesbah, A., Szenknect, S., Clavier, N., Lozano-Rodriguez, J., Poinssot, C., Den Auwer, C., Ewing, R. C., Dacheux, N. 2015; 54 (14): 6687-6696

    Abstract

    Coffinite, USiO4, is the second most abundant U(4+) mineral on Earth, and its formation by the alteration of the UO2 in spent nuclear fuel in a geologic repository may control the release of radionuclides to the environment. Despite its abundance in nature, the synthesis and characterization of coffinite have eluded researchers for decades. On the basis of the recent synthesis of USiO4, we can now define the experimental conditions under which coffinite is most efficiently formed. Optimal formation conditions are defined for four parameters: pH, T, heating time, and U/Si molar ratio. The adjustment of pH between 10 and 12 leads probably to the formation of a uranium(IV) hydroxo-silicate complex that acts as a precursor of uranium(IV) silicate colloids and then of coffinite. Moreover, in this pH range, the largest yield of coffinite formation (as compared with those of the two competing byproduct phases, nanometer-scale UO2 and amorphous SiO2) is obtained for 250 °C, 7 days, and 100% excess silica.

    View details for DOI 10.1021/ic502808n

    View details for Web of Science ID 000358549300005

    View details for PubMedID 26145720

  • Response of Gd2Ti2O7 and La2Ti2O7 to swift-heavy ion irradiation and annealing ACTA MATERIALIA Park, S., Lang, M., Tracy, C. L., Zhang, J., Zhang, F., Trautmann, C., Rodriguez, M. D., Kluth, P., Ewing, R. C. 2015; 93: 1-11
  • In situ defect annealing of swift heavy ion irradiated CeO2 and ThO2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell JOURNAL OF APPLIED CRYSTALLOGRAPHY Palomares, R. I., Tracy, C. L., Zhang, F., Park, C., Popov, D., Trautmann, C., Ewing, R. C., Lang, M. 2015; 48: 711-717
  • Thermodynamics of formation of coffinite, USiO4 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Guo, X., Szenknect, S., Mesbah, A., Labs, S., Clavier, N., Poinssot, C., Ushakov, S. V., Curtius, H., Bosbach, D., Ewing, R. C., Burns, P. C., Dacheux, N., Navrotsky, A. 2015; 112 (21): 6551-6555

    Abstract

    Coffinite, USiO4, is an important U(IV) mineral, but its thermodynamic properties are not well-constrained. In this work, two different coffinite samples were synthesized under hydrothermal conditions and purified from a mixture of products. The enthalpy of formation was obtained by high-temperature oxide melt solution calorimetry. Coffinite is energetically metastable with respect to a mixture of UO2 (uraninite) and SiO2 (quartz) by 25.6 ± 3.9 kJ/mol. Its standard enthalpy of formation from the elements at 25 °C is -1,970.0 ± 4.2 kJ/mol. Decomposition of the two samples was characterized by X-ray diffraction and by thermogravimetry and differential scanning calorimetry coupled with mass spectrometric analysis of evolved gases. Coffinite slowly decomposes to U3O8 and SiO2 starting around 450 °C in air and thus has poor thermal stability in the ambient environment. The energetic metastability explains why coffinite cannot be synthesized directly from uraninite and quartz but can be made by low-temperature precipitation in aqueous and hydrothermal environments. These thermochemical constraints are in accord with observations of the occurrence of coffinite in nature and are relevant to spent nuclear fuel corrosion.

    View details for DOI 10.1073/pnas.1507441112

    View details for Web of Science ID 000355213200029

    View details for PubMedID 25964321

    View details for PubMedCentralID PMC4450415

  • Characterization of ion-induced radiation effects in nuclear materials using synchrotron x-ray techniques JOURNAL OF MATERIALS RESEARCH Lang, M., Tracy, C. L., Palomares, R. I., Zhang, F., Severin, D., Bender, M., Trautmann, C., Park, C., Prakapenka, V. B., Skuratov, V. A., Ewing, R. C. 2015; 30 (9): 1366-1379

    View details for DOI 10.1557/jmr.2015.6

    View details for Web of Science ID 000355283500016

  • Ion-beam irradiation and Cm-244-doping investigations of the radiation response of actinide-bearing crystalline waste forms JOURNAL OF MATERIALS RESEARCH Yudintsev, S. V., Lizin, A. A., Livshits, T. S., Stefanovsky, S. V., Tomilin, S. V., Ewing, R. C. 2015; 30 (9): 1516-1528
  • Atomic disorder in Gd2Zr2O7 pyrochlore APPLIED PHYSICS LETTERS Zhang, F. X., Lang, M., Ewing, R. C. 2015; 106 (19)

    View details for DOI 10.1063/1.4921268

    View details for Web of Science ID 000355008100012

  • Uranium reduction on magnetite: Probing for pentavalent uranium using electrochemical methods GEOCHIMICA ET COSMOCHIMICA ACTA Yuan, K., Renock, D., Ewing, R. C., Becker, U. 2015; 156: 194-206
  • Ultrafast laser and swift heavy ion irradiation: Response of Gd2O3 and ZrO2 to intense electronic excitation APPLIED PHYSICS LETTERS Rittman, D. R., Tracy, C. L., Cusick, A. B., Abere, M. J., Torralva, B., Ewing, R. C., Yalisove, S. M. 2015; 106 (17)

    View details for DOI 10.1063/1.4919720

    View details for Web of Science ID 000353839100029

  • Constraints on Hf and Zr mobility in high-sulfidation epithermal systems: formation of kosnarite, KZr2(PO4)(3), in the Chaquicocha gold deposit, Yanacocha district, Peru MINERALIUM DEPOSITA Deditius, A. P., Utsunomiya, S., Sanchez-Alfaro, P., Reich, M., Ewing, R. C., Kesler, S. E. 2015; 50 (4): 429-436
  • Thermodynamic mixing properties of the UO2-HfO2 solid solution: Density functional theory and Monte Carlo simulations JOURNAL OF NUCLEAR MATERIALS Yuan, K., Ewing, R. C., Becker, U. 2015; 458: 296-303
  • The behavior of rare-earth pyrochlores and perovskites under ion irradiation DOKLADY EARTH SCIENCES Yudintsev, S. V., Livshits, T. S., Zhang, J., Ewing, R. C. 2015; 461 (1): 247-253
  • Long-term storage of spent nuclear fuel. Nature materials Ewing, R. C. 2015; 14 (3): 252-257

    View details for DOI 10.1038/nmat4226

    View details for PubMedID 25698421

  • Role of vein-phases in nanoscale sequestration of U, Nb, Ti, and Pb during the alteration of pyrochlore GEOCHIMICA ET COSMOCHIMICA ACTA Deditius, A. P., Smith, F. N., Utsunomiya, S., Ewing, R. C. 2015; 150: 226-252
  • Redox response of actinide materials to highly ionizing radiation NATURE COMMUNICATIONS Tracy, C. L., Lang, M., Pray, J. M., Zhang, F., Popov, D., Park, C., Trautmann, C., Bender, M., Severin, D., Skuratov, V. A., Ewing, R. C. 2015; 6

    Abstract

    Energetic radiation can cause dramatic changes in the physical and chemical properties of actinide materials, degrading their performance in fission-based energy systems. As advanced nuclear fuels and wasteforms are developed, fundamental understanding of the processes controlling radiation damage accumulation is necessary. Here we report oxidation state reduction of actinide and analogue elements caused by high-energy, heavy ion irradiation and demonstrate coupling of this redox behaviour with structural modifications. ThO2, in which thorium is stable only in a tetravalent state, exhibits damage accumulation processes distinct from those of multivalent cation compounds CeO2 (Ce(3+) and Ce(4+)) and UO3 (U(4+), U(5+) and U(6+)). The radiation tolerance of these materials depends on the efficiency of this redox reaction, such that damage can be inhibited by altering grain size and cation valence variability. Thus, the redox behaviour of actinide materials is important for the design of nuclear fuels and the prediction of their performance.

    View details for DOI 10.1038/ncomms7133

    View details for Web of Science ID 000348832300004

    View details for PubMedID 25626111

  • Photothermal effects and toxicity of Fe3O4 nanoparticles via near infrared laser irradiation for cancer therapy MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS Dunn, A. W., Ehsan, S. M., Mast, D., Pauletti, G. M., Xu, H., Zhang, J., Ewing, R. C., Shi, D. 2015; 46: 97-102

    Abstract

    The photothermal effect of magnetite (Fe3O4) nanoparticles was characterized by photonic absorption in the near-infrared (NIR) region. Upon laser irradiation at 785 nm, the Fe3O4 nanoparticles generate localized hyperthermia in tumorous lesions, which is an effective strategy for cancer therapy; however, uncoated magnetite possesses an innate toxicity which can lead to drawbacks in the clinical setting. To reduce innate toxicity, a poly(acrylic acid) (PAA) coating on the nanoparticles was investigated in order to determine the alterations to stability and the degree of toxicity in an attempt to create a higher utility vector. It was found that the PAA coating significantly reduced the innate toxicity of the uncoated magnetite. Furthermore, the efficacy of PAA-coated magnetite nanoparticles (PAA-Fe3O4) was investigated for treating MDA-MB-231 (human mammary gland adenocarcinoma) cultures in viable concentration ranges (0.1-0.5mg/ml). An appropriate PAA-Fe3O4 concentration range was then established for inducing significant cell death by hyperthermic ablation, but not through innate toxicity.

    View details for DOI 10.1016/j.msec.2014.09.043

    View details for Web of Science ID 000347757100012

    View details for PubMedID 25491964

  • Carbonate orientational order and superlattice structure in vaterite JOURNAL OF CRYSTAL GROWTH Wang, J., Zhang, F., Zhang, J., Ewing, R. C., Becker, U., Cai, Z. 2014; 407: 78-86
  • Incorporation of uranium in pyrochlore oxides and pressure-induced phase transitions JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Lang, M., Tracy, C., Ewing, R. C., Gregg, D. J., Lumpkin, G. R. 2014; 219: 49-54
  • Thermodynamics of thorium substitution in yttrium iron garnet: comparison of experimental and theoretical results JOURNAL OF MATERIALS CHEMISTRY A Guo, X., Rak, Z., Tavakoli, A. H., Becker, U., Ewing, R. C., Navrotsky, A. 2014; 2 (40): 16945-16954

    View details for DOI 10.1039/c4ta03683b

    View details for Web of Science ID 000343072300019

  • Swift heavy ion track formation in Gd2Zr2-xTixO7 pyrochlore: Effect of electronic energy loss NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Lang, M., Toulemonde, M., Zhang, J., Zhang, F., Tracy, C. L., Lian, J., Wang, Z., Weber, W. J., Severin, D., Bender, M., Trautmann, C., Ewing, R. C. 2014; 336: 102-115
  • Effect of spatial confinement on magnetic hyperthermia via dipolar interactions in Fe3O4 nanoparticles for biomedical applications. Materials science & engineering. C, Materials for biological applications Sadat, M. E., Patel, R., Sookoor, J., Bud'ko, S. L., Ewing, R. C., Zhang, J., Xu, H., Wang, Y., Pauletti, G. M., Mast, D. B., Shi, D. 2014; 42: 52-63

    Abstract

    In this work, the effect of nanoparticle confinement on the magnetic relaxation of iron oxide (Fe3O4) nanoparticles (NP) was investigated by measuring the hyperthermia heating behavior in high frequency alternating magnetic field. Three different Fe3O4 nanoparticle systems having distinct nanoparticle configurations were studied in terms of magnetic hyperthermia heating rate and DC magnetization. All magnetic nanoparticle (MNP) systems were constructed using equivalent ~10nm diameter NP that were structured differently in terms of configuration, physical confinement, and interparticle spacing. The spatial confinement was achieved by embedding the Fe3O4 nanoparticles in the matrices of the polystyrene spheres of 100nm, while the unconfined was the free Fe3O4 nanoparticles well-dispersed in the liquid via PAA surface coating. Assuming the identical core MNPs in each system, the heating behavior was analyzed in terms of particle freedom (or confinement), interparticle spacing, and magnetic coupling (or dipole-dipole interaction). DC magnetization data were correlated to the heating behavior with different material properties. Analysis of DC magnetization measurements showed deviation from classical Langevin behavior near saturation due to dipole interaction modification of the MNPs resulting in a high magnetic anisotropy. It was found that the Specific Absorption Rate (SAR) of the unconfined nanoparticle systems were significantly higher than those of confined (the MNPs embedded in the polystyrene matrix). This increase of SAR was found to be attributable to high Néel relaxation rate and hysteresis loss of the unconfined MNPs. It was also found that the dipole-dipole interactions can significantly reduce the global magnetic response of the MNPs and thereby decrease the SAR of the nanoparticle systems.

    View details for DOI 10.1016/j.msec.2014.04.064

    View details for PubMedID 25063092

  • Defect formation energy in pyrochlore: the effect of crystal size MATERIALS RESEARCH EXPRESS Wang, J., Ewing, R. C., Becker, U. 2014; 1 (3)
  • Photoluminescence and photothermal effect of Fe3O4 nanoparticles for medical imaging and therapy APPLIED PHYSICS LETTERS Sadat, M. E., Baghbador, M. K., Dunn, A. W., Wagner, H. P., Ewing, R. C., Zhang, J., Xu, H., Pauletti, G. M., Mast, D. B., Shi, D. 2014; 105 (9)

    View details for DOI 10.1063/1.4895133

    View details for Web of Science ID 000342749800017

  • The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits GEOCHIMICA ET COSMOCHIMICA ACTA Deditius, A. P., Reich, M., Kesler, S. E., Utsunomiya, S., Chryssoulis, S. L., Walshe, J., Ewing, R. C. 2014; 140: 644-670
  • Dipole-interaction mediated hyperthermia heating mechanism of nanostructured Fe3O4 composites MATERIALS LETTERS Sadat, M. E., Patel, R., Bud'ko, S. L., Ewing, R. C., Zhang, J., Xue, H., Mast, D. B., Shi, D. 2014; 129: 57-60
  • Bulk Iodoapatite Ceramic Densified by Spark Plasma Sintering with Exceptional Thermal Stability JOURNAL OF THE AMERICAN CERAMIC SOCIETY Yao, T., Lu, F., Sun, H., Wang, J., Ewing, R. C., Lian, J. 2014; 97 (8): 2409-2412

    View details for DOI 10.1111/jace.13101

    View details for Web of Science ID 000340529200017

  • Effect of orientation on ion track formation in apatite and zircon AMERICAN MINERALOGIST Li, W., Kluth, P., Schauries, D., Rodriguez, M. D., Lang, M., Zhang, F., Zdorovets, M., Trautmann, C., Ewing, R. C. 2014; 99 (5-6): 1127-1132
  • Presentation of the Distinguished Public Service Award for 2013 of the Mineralogical Society of America to Pierrette Tremblay AMERICAN MINERALOGIST Ewing, R. C. 2014; 99 (5-6): 1185-1185
  • The shape of ion tracks in natural apatite NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Schauries, D., Afra, B., Bierschenk, T., Lang, M., Rodriguez, M. D., Trautmann, C., Li, W., Ewing, R. C., Kluth, P. 2014; 326: 117-120
  • Swift heavy ion-induced phase transformation in Gd2O3 NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Lang, M., Zhang, F., Zhang, J., Tracy, C. L., Cusick, A. B., VonEhr, J., Chen, Z., Trautmann, C., Ewing, R. C. 2014; 326: 121-125
  • High-pressure U3O8 with the fluorite-type structure JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Lang, M., Wang, J. W., Li, W. X., Sun, K., Prakapenka, V., Ewing, R. C. 2014; 213: 110-115
  • Defect accumulation in ThO2 irradiated with swift heavy ions NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Tracy, C. L., Pray, J. M., Lang, M., Popov, D., Park, C., Trautmann, C., Ewing, R. C. 2014; 326: 169-173
  • SAXS and TEM investigation of ion tracks in neodymium-doped yttrium aluminium garnet NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Rodriguez, M. D., Li, W. X., Chen, F., Trautmann, C., Bierschenk, T., Afra, B., Schauries, D., Ewing, R. C., Mudie, S. T., Kluth, P. 2014; 326: 150-153
  • Annealing behaviour of ion tracks in olivine, apatite and britholite NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Afra, B., Lang, M., Bierschenk, T., Rodriguez, M. D., Weber, W. J., Trautmann, C., Ewing, R. C., Kirby, N., Kluth, P. 2014; 326: 126-130
  • Swift heavy ion irradiation-induced amorphization of La2Ti2O7 NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Park, S., Lang, M., Tracy, C. L., Zhang, J., Zhang, F., Trautmann, C., Kluth, P., Rodriguez, M. D., Ewing, R. C. 2014; 326: 145-149
  • Average structure and local configuration of excess oxygen in UO2+x SCIENTIFIC REPORTS Wang, J., Ewing, R. C., Becker, U. 2014; 4

    Abstract

    Determination of the local configuration of interacting defects in a crystalline, periodic solid is problematic because defects typically do not have a long-range periodicity. Uranium dioxide, the primary fuel for fission reactors, exists in hyperstoichiometric form, UO(2+x). Those excess oxygen atoms occur as interstitial defects, and these defects are not random but rather partially ordered. The widely-accepted model to date, the Willis cluster based on neutron diffraction, cannot be reconciled with the first-principles molecular dynamics simulations present here. We demonstrate that the Willis cluster is a fair representation of the numerical ratio of different interstitial O atoms; however, the model does not represent the actual local configuration. The simulations show that the average structure of UO(2+x) involves a combination of defect structures including split di-interstitial, di-interstitial, mono-interstitial, and the Willis cluster, and the latter is a transition state that provides for the fast diffusion of the defect cluster. The results provide new insights in differentiating the average structure from the local configuration of defects in a solid and the transport properties of UO(2+x).

    View details for DOI 10.1038/srep04216

    View details for Web of Science ID 000333017000001

    View details for PubMedID 24642875

    View details for PubMedCentralID PMC3958918

  • Three New Silver Uranyl Diphosphonates: Structures and Properties INORGANIC CHEMISTRY Nelson, A. D., Rak, Z., Abrecht-Schmitt, T. E., Becker, U., Ewing, R. C. 2014; 53 (6): 2787-2796

    Abstract

    The hydrothermal reaction of uranium trioxide and methylenediphosphonic acid in the presence of silver nitrate resulted in the formation of three new uranyl coordination polymers: AgUO2[CH2(PO3)(PO3H)] (Ag-1), [Ag2(H2O)1.5]{(UO2)2[CH2(PO3)2]F2}·(H2O)0.5 (Ag-2), and Ag2UO2[CH2(PO3)2] (Ag-3). All consist of uranyl pentagonal bipyramids that form two-dimensional layered structures. Ag-1 and Ag-3 possess the same structural building unit, but the structures are different; Ag-3 is formed through edge-sharing of F atoms to form UO5F2 dimers. The pH and silver cation have significant effects on the structure that is synthesized. Raman spectra of single crystals of Ag-1, Ag-2, and Ag-3 reveal v1 UO2(2+) symmetric stretches of 816 and 829, 822, and 802 cm(-1), respectively. Electronic structure calculations were performed using the projector augmented wave (PAW) method with density functional theory (DFT) to gain insight into the nature of bonding and electronic characteristics of the synthesized compounds. Herein, we report the syntheses, crystal structures, Raman spectroscopy, and luminescent behavior of these three compounds.

    View details for DOI 10.1021/ic401897n

    View details for Web of Science ID 000333142800008

    View details for PubMedID 24524249

  • Molten salts activated by high-energy milling: A useful, low-temperature route for the synthesis of multiferroic compounds JOURNAL OF ALLOYS AND COMPOUNDS Hernandez-Ramirez, A., Martinez-Luevanos, A., Fuentes, A. F., Nelson, A. D., Ewing, R. C., Montemayor, S. M. 2014; 584: 93-100
  • Nano-porosity in GaSb induced by swift heavy ion irradiation APPLIED PHYSICS LETTERS Kluth, P., Sullivan, J., Li, W., Weed, R., Schnohr, C. S., Giulian, R., Araujo, L. L., Lei, W., Rodriguez, M. D., Afra, B., Bierschenk, T., Ewing, R. C., Ridgway, M. C. 2014; 104 (2)

    View details for DOI 10.1063/1.4861747

    View details for Web of Science ID 000330431000093

  • Facile low temperature solid state synthesis of iodoapatite by high-energy ball milling RSC ADVANCES Lu, F., Yao, T., Xu, J., Wang, J., Scott, S., Dong, Z., Ewing, R. C., Lian, J. 2014; 4 (73): 38718-38725

    View details for DOI 10.1039/c4ra05320f

    View details for Web of Science ID 000341776900031

  • Electronic structure and thermodynamic stability of uranium-doped yttrium iron garnet JOURNAL OF PHYSICS-CONDENSED MATTER Rak, Z., Ewing, R. C., Becker, U. 2013; 25 (49)

    Abstract

    The electronic and thermodynamic properties of yttrium iron garnet (Y3Fe5O12, YIG), as a possible uranium-bearing phase, have been investigated using first-principles and semi-empirical methods. The electronic structures of pure and U-doped YIG were calculated and compared in order to obtain a fundamental understanding of the incorporation mechanism and stability of U in a YIG matrix. Uranium at the A-site is in 4 +  oxidation state, acting as a single donor and introducing a localized defect state in the band gap. The ionic relaxations show U at the A-site is an off-center impurity. At the B-site, uranium is in 5 +  oxidation state giving rise to two localized defect states in the middle of the band gap. At thermodynamic equilibrium the incorporation of U is limited by (i) the relatively narrow stability domain of the host YIG and (ii) the precipitation of uranium oxides as secondary phases. Under Y-rich growth conditions, YIG is unstable with respect to competing phases such as the iron oxides, Y2O3 and YFeO3. Under O-rich conditions, the incorporation U is obstructed by the formation of uranium-oxide precipitates. Under Fe-rich growth conditions, the formation energies of UY (U at the A-site) and UFe (U at the B-site) become negative for 0 ≤ EF ≤ 0.62 eV and 0 ≤ EF ≤ 0.77 eV, respectively, indicating that U might be incorporated in p-type YIG.

    View details for DOI 10.1088/0953-8984/25/49/495502

    View details for Web of Science ID 000327181400007

    View details for PubMedID 24184778

  • Temperature dependence of ion track formation in quartz and apatite JOURNAL OF APPLIED CRYSTALLOGRAPHY Schauries, D., Lang, M., Pakarinen, O. H., Botis, S., Afra, B., Rodriguez, M. D., Djurabekova, F., Nordlund, K., Severin, D., Bender, M., Li, W. X., Trautmann, C., Ewing, R. C., Kirby, N., Kluth, P. 2013; 46: 1558-1563
  • A self-consistent model describing the thermodynamics of Eu(III) adsorption onto hematite GEOCHIMICA ET COSMOCHIMICA ACTA Estes, S. L., Arai, Y., Becker, U., Fernando, S., Yuan, K., Ewing, R. C., Zhang, J., Shibata, T., Powell, B. A. 2013; 122: 430-447
  • Structure and properties of rare earth silicates with the apatite structure at high pressure PHYSICS AND CHEMISTRY OF MINERALS Zhang, F. X., Xiao, H. Y., Lang, M., ZHANG, J. M., Zhang, Y., Weber, W. J., Ewing, R. C. 2013; 40 (10): 817-825
  • The energetics and kinetics of uranyl reduction on pyrite, hematite, and magnetite surfaces: A powder microelectrode study GEOCHIMICA ET COSMOCHIMICA ACTA Renock, D., Mueller, M., Yuan, K., Ewing, R. C., Becker, U. 2013; 118: 56-71
  • Sb2Se3 under pressure SCIENTIFIC REPORTS Efthimiopoulos, I., Zhang, J., Kucway, M., Park, C., Ewing, R. C., Wang, Y. 2013; 3

    Abstract

    Selected members of the A₂B₃ (A = Sb, Bi; B = Se, Te) family are topological insulators. The Sb₂Se₃ compound does not exhibit any topological properties at ambient conditions; a recent high-pressure study, however, indicated that pressure transforms Sb₂Se₃ from a band insulator into a topological insulator above ~2 GPa; in addition, three structural transitions were proposed to occur up to 25 GPa. Partly motivated by these results, we have performed x-ray diffraction and Raman spectroscopy investigations on Sb₂Se₃ under pressure up to 65 GPa. We have identified only one reversible structural transition: the initial Pnma structure transforms into a disordered cubic bcc alloy above 51 GPa. On the other hand, our high-pressure Raman study did not reproduce the previous results; we attribute the discrepancies to the effects of the different pressure transmitting media used in the high-pressure experiments. We discuss the structural behavior of Sb₂Se₃ within the A₂B₃ (A = Sb, Bi; B = Se, Te) series.

    View details for DOI 10.1038/srep02665

    View details for Web of Science ID 000324536400001

    View details for PubMedID 24045363

  • The CRAPome: a contaminant repository for affinity purification-mass spectrometry data NATURE METHODS Mellacheruvu, D., Wright, Z., Couzens, A. L., Lambert, J., St-Denis, N. A., Li, T., Miteva, Y. V., Hauri, S., Sardiu, M. E., Low, T. Y., Halim, V. A., Bagshaw, R. D., Hubner, N. C., Al-Hakim, A., Bouchard, A., Faubert, D., Fermin, D., Dunham, W. H., Goudreault, M., Lin, Z., Badillo, B. G., Pawson, T., Durocher, D., Coulombe, B., Aebersold, R., Superti-Furga, G., Colinge, J., Heck, A. J., Choi, H., Gstaiger, M., Mohammed, S., Cristea, I. M., Bennett, K. L., Washburn, M. P., Raught, B., Ewing, R. M., Gingras, A., Nesvizhskii, A. I. 2013; 10 (8): 730-?

    Abstract

    Affinity purification coupled with mass spectrometry (AP-MS) is a widely used approach for the identification of protein-protein interactions. However, for any given protein of interest, determining which of the identified polypeptides represent bona fide interactors versus those that are background contaminants (for example, proteins that interact with the solid-phase support, affinity reagent or epitope tag) is a challenging task. The standard approach is to identify nonspecific interactions using one or more negative-control purifications, but many small-scale AP-MS studies do not capture a complete, accurate background protein set when available controls are limited. Fortunately, negative controls are largely bait independent. Hence, aggregating negative controls from multiple AP-MS studies can increase coverage and improve the characterization of background associated with a given experimental protocol. Here we present the contaminant repository for affinity purification (the CRAPome) and describe its use for scoring protein-protein interactions. The repository (currently available for Homo sapiens and Saccharomyces cerevisiae) and computational tools are freely accessible at http://www.crapome.org/.

    View details for DOI 10.1038/nmeth.2557

    View details for Web of Science ID 000322453600019

    View details for PubMedID 23921808

  • Electronic structure and stability of hyperstoichiometric UO2+x under pressure PHYSICAL REVIEW B Wang, J., Ewing, R. C., Becker, U. 2013; 88 (2)
  • Dual Surface-Functionalized Janus Nanocomposites of Polystyrene/Fe3O4@SiO2 for Simultaneous Tumor Cell Targeting and Stimulus-Induced Drug Release ADVANCED MATERIALS Wang, F., Pauletti, G. M., Wang, J., Zhang, J., Ewing, R. C., Wang, Y., Shi, D. 2013; 25 (25): 3485-3489
  • Ion-irradiation-induced structural transitions in orthorhombic Ln(2)TiO(5) ACTA MATERIALIA Zhang, J., Zhang, F., Lang, M., Lu, F., Lian, J., Ewing, R. C. 2013; 61 (11): 4191-4199
  • Ferric garnet matrices for immobilization of actinides JOURNAL OF NUCLEAR MATERIALS Rak, Z., Ewing, R. C., Becker, U. 2013; 436 (1-3): 1-7
  • Size dependence of radiation-induced amorphization and recrystallization of synthetic nanostructured CePO4 monazite ACTA MATERIALIA Lu, F., Shen, Y., Sun, X., Dong, Z., Ewing, R. C., Lian, J. 2013; 61 (8): 2984-2992
  • Effect of doping on the radiation response of conductive Nb-SrTiO3 NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Li, W., Rodriguez, M. D., Kluth, P., Lang, M., Medvedev, N., Sorokin, M., Zhang, J., Afra, B., Bender, M., Severin, D., Trautmann, C., Ewing, R. C. 2013; 302: 40-47
  • Multi-scale simulation of structural heterogeneity of swift-heavy ion tracks in complex oxides JOURNAL OF PHYSICS-CONDENSED MATTER Wang, J., Lang, M., Ewing, R. C., Becker, U. 2013; 25 (13)
  • Hydrogen incorporation in crystalline zircon: Insight from ab initio calculations AMERICAN MINERALOGIST Botis, S. M., Pan, Y., Ewing, R. C. 2013; 98 (4): 745-751
  • Np-incorporation into uranyl phases: A quantum-mechanical evaluation JOURNAL OF NUCLEAR MATERIALS Shuller, L. C., Ewing, R. C., Becker, U. 2013; 434 (1-3): 440-450
  • Charge distribution and oxygen diffusion in hyperstoichiometric uranium dioxide UO2+x (x <= 0.25) JOURNAL OF NUCLEAR MATERIALS Skomurski, F. N., Wang, J. W., Ewing, R. C., Becker, U. 2013; 434 (1-3): 422-433
  • A Versatile Multicomponent Assembly via -cyclodextrin HostGuest Chemistry on Graphene for Biomedical Applications SMALL Dong, H., Li, Y., Yu, J., Song, Y., Cai, X., Liu, J., Zhang, J., Ewing, R. C., Shi, D. 2013; 9 (3): 446-456

    Abstract

    A multi-component nanosystem based on graphene and comprising individual cyclodextrins at its surface is assembled, creating hybrid structures enabling new and important functionalities: optical imaging, drug storage, and cell targeting for medical diagnosis and treatment. These nanohybrids are part of a universal system of interchangeable units, capable of mutilple functionalities. The surface components, made of individual β-cyclodextrin molecules, are the "hosts" for functional units, which may be used as imaging agents, for anti-cancer drug delivery, and as tumor-specific ligands. Specifically, individual β-cyclodextrin (β-CD), with a known capability to host various molecules, is considered a module unit that is assembled onto graphene nanosheet (GNS). The cyclodextrin-functionalized graphene nanosheet (GNS/β-CD) enables "host-guest" chemistry between the nanohybrid and functional "payloads". The structure, composition, and morphology of the graphene nanosheet hybrid have been investigated. The nanohybrid, GNS/β-CD, is highly dispersive in various physiological solutions, reflecting the high biostability of cyclodextrin. Regarding the host capability, the nanohybrid is fully capable of selectively accommodating various biological and functional agents in a controlled fashion, including the antivirus drug amantadine, fluorescent dye [5(6)-carboxyfluorescein], and Arg-Gly-Asp (RGD) peptide-targeting ligands assisted by an adamantine linker. The loading ratio of 5(6)-carboxyfluorescein is as high as 110% with a drug concentration of 0.45 mg mL(-1). The cyclic RGD-functionalized nanohybrid exhibits remarkable targeting for HeLa cells.

    View details for DOI 10.1002/smll.201201003

    View details for Web of Science ID 000314547200016

    View details for PubMedID 23047287

  • Hydroxylation-induced surface stability of AnO(2) (An = U, Np, Pu) from first-principles SURFACE SCIENCE Rak, Z., Ewing, R. C., Becker, U. 2013; 608: 180-187
  • Uranium diphosphonates templated by interlayer organic amines JOURNAL OF SOLID STATE CHEMISTRY Nelson, A. D., Alekseev, E. V., Albrecht-Schmitt, T. E., Ewing, R. C. 2013; 198: 270-278
  • Multilayered YSZ/GZO films with greatly enhanced ionic conduction for low temperature solid oxide fuel cells PHYSICAL CHEMISTRY CHEMICAL PHYSICS Li, B., Zhang, J., Kaspar, T., Shutthanandan, V., Ewing, R. C., Lian, J. 2013; 15 (4): 1296-1301

    View details for DOI 10.1039/c2cp42964k

    View details for Web of Science ID 000312462400029

  • Atomistic calculations of the thermodynamic properties of mixing for tetravalent metal dioxide solid solutions: (Zr, Th, Ce)O-2 JOURNAL OF SOLID STATE CHEMISTRY Shuller-Nickles, L. C., Ewing, R. C., Becker, U. 2013; 197: 550-559
  • Tailoring the radiation tolerance of vanadate-phosphate fluorapatites by chemical composition control RSC ADVANCES Lu, F., Dong, Z., Zhang, J., White, T., Ewing, R. C., Lian, J. 2013; 3 (35): 15178-15184

    View details for DOI 10.1039/c3ra42246a

    View details for Web of Science ID 000323132100040

  • He diffusion and closure temperatures in apatite and zircon: A density functional theory investigation (vol 86, pg 228, 2012) GEOCHIMICA ET COSMOCHIMICA ACTA Bengtson, A., Ewing, R. C., Becker, U. 2012; 98: 202-202
  • Enhanced Energy Metabolism Contributes to the Extended Life Span of Calorie-restricted Caenorhabditis elegans JOURNAL OF BIOLOGICAL CHEMISTRY Yuan, Y., Kadiyala, C. S., Ching, T., Hakimi, P., Saha, S., Xu, H., Yuan, C., Mullangi, V., Wang, L., Fivenson, E., Hanson, R. W., Ewing, R., Hsu, A., Miyagi, M., Feng, Z. 2012; 287 (37): 31414-31426

    Abstract

    Caloric restriction (CR) markedly extends life span and improves the health of a broad number of species. Energy metabolism fundamentally contributes to the beneficial effects of CR, but the underlying mechanisms that are responsible for this effect remain enigmatic. A multidisciplinary approach that involves quantitative proteomics, immunochemistry, metabolic quantification, and life span analysis was used to determine how CR, which occurs in the Caenorhabditis elegans eat-2 mutants, modifies energy metabolism of the worm, and whether the observed modifications contribute to the CR-mediated physiological responses. A switch to fatty acid metabolism as an energy source and an enhanced rate of energy metabolism by eat-2 mutant nematodes were detected. Life span analyses validated the important role of these previously unknown alterations of energy metabolism in the CR-mediated longevity of nematodes. As observed in mice, the overexpression of the gene for the nematode analog of the cytosolic form of phosphoenolpyruvate carboxykinase caused a marked extension of the life span in C. elegans, presumably by enhancing energy metabolism via an altered rate of cataplerosis of tricarboxylic acid cycle anions. We conclude that an increase, not a decrease in fuel consumption, via an accelerated oxidation of fuels in the TCA cycle is involved in life span regulation; this mechanism may be conserved across phylogeny.

    View details for DOI 10.1074/jbc.M112.377275

    View details for Web of Science ID 000308791300052

    View details for PubMedID 22810224

  • Swift heavy ion irradiation of diamond powder 16th International Conference on Radiation Effects in Insulators (REI) Zhang, F., Lang, M., Zhang, J., Ewing, R. C. ELSEVIER SCIENCE BV. 2012: 262–265
  • Swift heavy ion-induced amorphization of CaZrO3 perovskite 16th International Conference on Radiation Effects in Insulators (REI) Lang, M., Zhang, F., Li, W., Severin, D., Bender, M., Klaumuenzer, S., Trautmann, C., Ewing, R. C. ELSEVIER SCIENCE BV. 2012: 271–276
  • First principles investigation of structural, electronic, elastic and thermal properties of rare-earth-doped titanate Ln(2)TiO(5) AIP ADVANCES Niu, H., Gou, H., Ewing, R. C., Lian, J. 2012; 2 (3)

    View details for DOI 10.1063/1.4739276

    View details for Web of Science ID 000309388800014

  • ZrSi formation at ZrN/Si interface induced by ballistic and ionizing radiations 16th International Conference on Radiation Effects in Insulators (REI) Lu, F., Lang, M., Huang, M., Namavar, F., Trautmann, C., Ewing, R. C., Lian, J. ELSEVIER SCIENCE BV. 2012: 266–270
  • Barium uranyl diphosphonates JOURNAL OF SOLID STATE CHEMISTRY Nelson, A. D., Alekseev, E. V., Ewing, R. C., Albrecht-Schmitt, T. E. 2012; 192: 153-160
  • Displacive radiation-induced structural contraction in nanocrystalline ZrN APPLIED PHYSICS LETTERS Lu, F., Huang, M., Yaqoob, F., Lang, M., Namavar, F., Trautmann, C., Sun, H., Ewing, R. C., Lian, J. 2012; 101 (4)

    View details for DOI 10.1063/1.4738772

    View details for Web of Science ID 000306944700027

  • Lead in zircon at the atomic scale AMERICAN MINERALOGIST Kogawa, M., Watson, E. B., Ewing, R. C., Utsunomiya, S. 2012; 97 (7): 1094-1102
  • Phase transition and abnormal compressibility of lanthanide silicate with the apatite structure PHYSICAL REVIEW B Zhang, F. X., Lang, M., ZHANG, J. M., Cheng, Z. Q., Liu, Z. X., Lian, J., Ewing, R. C. 2012; 85 (21)
  • Human Biomarker Discovery and Predictive Models for Disease Progression for Idiopathic Pneumonia Syndrome Following Allogeneic Stem Cell Transplantation MOLECULAR & CELLULAR PROTEOMICS Schlatzer, D. M., Dazard, J., Ewing, R. M., Ilchenko, S., Tomcheko, S. E., Eid, S., Ho, V., Yanik, G., Chance, M. R., Cooke, K. R. 2012; 11 (6)

    Abstract

    Allogeneic hematopoietic stem cell transplantation (SCT) is the only curative therapy for many malignant and nonmalignant conditions. Idiopathic pneumonia syndrome (IPS) is a frequently fatal complication that limits successful outcomes. Preclinical models suggest that IPS represents an immune mediated attack on the lung involving elements of both the adaptive and the innate immune system. However, the etiology of IPS in humans is less well understood. To explore the disease pathway and uncover potential biomarkers of disease, we performed two separate label-free, proteomics experiments defining the plasma protein profiles of allogeneic SCT patients with IPS. Samples obtained from SCT recipients without complications served as controls. The initial discovery study, intended to explore the disease pathway in humans, identified a set of 81 IPS-associated proteins. These data revealed similarities between the known IPS pathways in mice and the condition in humans, in particular in the acute phase response. In addition, pattern recognition pathways were judged to be significant as a function of development of IPS, and from this pathway we chose the lipopolysaccaharide-binding protein (LBP) protein as a candidate molecular diagnostic for IPS, and verified its increase as a function of disease using an ELISA assay. In a separately designed study, we identified protein-based classifiers that could predict, at day 0 of SCT, patients who: 1) progress to IPS and 2) respond to cytokine neutralization therapy. Using cross-validation strategies, we built highly predictive classifier models of both disease progression and therapeutic response. In sum, data generated in this report confirm previous clinical and experimental findings, provide new insights into the pathophysiology of IPS, identify potential molecular classifiers of the condition, and uncover a set of markers potentially of interest for patient stratification as a basis for individualized therapy.

    View details for DOI 10.1074/mcp.M111.015479

    View details for Web of Science ID 000306408500033

    View details for PubMedID 22337588

  • Fukushima Daiichi: More Than One Year Later ELEMENTS Ewing, R. C., Murakami, T. 2012; 8 (3): 181-182
  • He diffusion and closure temperatures in apatite and zircon: A density functional theory investigation GEOCHIMICA ET COSMOCHIMICA ACTA Bengtson, A., Ewing, R. C., Becker, U. 2012; 86: 228-238
  • Structural response of A(2)TiO(5) (A = La, Nd, Sm, Gd) to swift heavy ion irradiation ACTA MATERIALIA Tracy, C. L., Lang, M., Zhang, J., Zhang, F., Wang, Z., Ewing, R. C. 2012; 60 (11): 4477-4486
  • Time to bury plutonium NATURE von Hippel, F., Ewing, R., Garwin, R., Macfarlane, A. 2012; 485 (7397): 167-168
  • Effect of interstitial atoms on the stability and electronic structure of Re3Zn alloy: First-principles calculations INTERMETALLICS Gou, H., Li, J., Li, H., Zhang, H., Li, Z., Ewing, R. C., Lian, J. 2012; 24: 95-98
  • Is nuclear fission a sustainable source of energy? MRS BULLETIN Englert, M., Krall, L., Ewing, R. C. 2012; 37 (4): 417-424

    View details for DOI 10.1557/mrs.2012.6

    View details for Web of Science ID 000302472500015

  • Formation of nanoscale Th-coffinite AMERICAN MINERALOGIST Deditius, A. P., Pointeau, V., Zhang, J. M., Ewing, R. C. 2012; 97 (4): 681-693
  • Phase composition and radiation stability of matrices for isolation of REE-actinide waste DOKLADY EARTH SCIENCES Laverov, N. P., Yudintsev, S. V., Stefanovsky, S. V., Ewing, R. C. 2012; 443 (2): 526-531
  • Unusual rigidity and ideal strength of CrB4 and MnB4 APPLIED PHYSICS LETTERS Gou, H., Li, Z., Niu, H., Gao, F., Zhang, J., Ewing, R. C., Lian, J. 2012; 100 (11)

    View details for DOI 10.1063/1.3692777

    View details for Web of Science ID 000302204900030

  • Nuclear Fuel in a Reactor Accident SCIENCE Burns, P. C., Ewing, R. C., Navrotsky, A. 2012; 335 (6073): 1184-1188

    Abstract

    Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with water, after an accident remain limited. Relatively little is known about fuel corrosion and radionuclide release under the extreme chemical, radiation, and thermal conditions during and subsequent to a nuclear accident. We review the current understanding of nuclear fuel interactions with the environment, including studies over the relatively narrow range of geochemical, hydrological, and radiation environments relevant to geological repository performance, and discuss priorities for research needed to develop future predictive models.

    View details for DOI 10.1126/science.1211285

    View details for Web of Science ID 000301225100034

    View details for PubMedID 22403382

  • Thermal annealing of unetched fission tracks in apatite EARTH AND PLANETARY SCIENCE LETTERS Li, W., Lang, M., Gleadow, A. J., Zdorovets, M. V., Ewing, R. C. 2012; 321: 121-127
  • Origin of the rigidity in tetragonal MB (M = Cr, Mo and W) and softening of defective WB: First-principles investigations COMPUTATIONAL MATERIALS SCIENCE Gou, H., Li, Z., Zhang, J., Niu, H., Gao, F., Ewing, R. C., Lian, J. 2012; 53 (1): 460-463
  • Controlling the Structure and Size of Au Nanocrystals by Annealing and Ion Sputtering LANGMUIR Li, W., Chen, Y., Zhang, J., Wang, L., Ewing, R. C. 2012; 28 (1): 51-55

    Abstract

    In situ thermal annealing was used for the first time to observe directly that Au nanoparticles, which were originally fully embedded in the near-surface region of TiO(2), can be tailored into hemispheres exposed at the surface at elevated temperature. Precise control of the size of the Au hemispheres was achieved by subsequent low-energy ion sputtering. This method can be used to control the structure and size of a wide variety of nanoparticles in a matrix where surface structure and particle size are required to obtain specific material properties.

    View details for DOI 10.1012/la204016v

    View details for Web of Science ID 000298904900011

    View details for PubMedID 22142251

  • In situ AFM and XPS Investigation of U6+ Reduction by Fe2+ on Hematite and Pyrite MRS Spring Meeting Niu, J., Becker, U., Ewing, R. MATERIALS RESEARCH SOC. 2012: 243–248
  • Morphology and annealing kinetics of ion tracks in minerals 1st Heavy Ion Accelerator Symposium on Fundamental and Applied Science (HIAS) Kluth, P., Afra, B., Rodriguez, M. D., Lang, M., Trautmann, C., Ewing, R. C. E D P SCIENCES. 2012
  • Amorphization of nanocrystalline monoclinic ZrO2 by swift heavy ion irradiation PHYSICAL CHEMISTRY CHEMICAL PHYSICS Lu, F., Wang, J., Lang, M., Toulemonde, M., Namavar, F., Trautmann, C., Zhang, J., Ewing, R. C., Lian, J. 2012; 14 (35): 12295-12300

    Abstract

    Bulk ZrO(2) polymorphs generally have an extremely high amorphization tolerance upon low energy ion and swift heavy ion irradiation in which ballistic interaction and ionization radiation dominate the ion-solid interaction, respectively. However, under very high-energy irradiation by 1.33 GeV U-238, nanocrystalline (40-50 nm) monoclinic ZrO(2) can be amorphized. A computational simulation based on a thermal spike model reveals that the strong ionizing radiation from swift heavy ions with a very high electronic energy loss of 52.2 keV nm(-1) can induce transient zones with temperatures well above the ZrO(2) melting point. The extreme electronic energy loss, coupled with the high energy state of the nanostructured materials and a high thermal confinement due to the less effective heat transport within the transient hot zone, may eventually be responsible for the ionizing radiation-induced amorphization without transforming to the tetragonal polymorph. The amorphization of nanocrystalline zirconia was also confirmed by 1.69 GeV Au ion irradiation with the electronic energy loss of 40 keV nm(-1). These results suggest that highly radiation tolerant materials in bulk forms, such as ZrO(2), may be radiation sensitive with the reduced length scale down to the nano-metered regime upon irradiation above a threshold value of electronic energy loss.

    View details for DOI 10.1039/c2cp41553d

    View details for Web of Science ID 000307648700031

    View details for PubMedID 22858872

  • Nanosized Rutile (TiO2) Thin Film upon Ion Irradiation and Thermal Annealing JOURNAL OF PHYSICAL CHEMISTRY C Zhang, J., Lian, J., Namavar, F., Wang, J., Haider, H., Garvin, K., Ewing, R. C. 2011; 115 (46): 22755-22760

    View details for DOI 10.1021/jp2056283

    View details for Web of Science ID 000297001000009

  • Electronic structure and energetics of tetragonal SrCuO2 and its high-pressure superstructure phase JOURNAL OF PHYSICS-CONDENSED MATTER Wang, J., Rak, Z., Zhang, F., Ewing, R. C., Becker, U. 2011; 23 (46)

    Abstract

    First-principles calculations have been used to investigate the electronic structure and energetics of the simple tetragonal SrCuO₂ (P4=mmm) and its high-pressure tetragonal superstructure (P4=mmm). Based on the calculations, the high-pressure phase is metastable as compared with the low pressure tetragonal phase, with an energy difference of 0.13 eV per SrCuO₂ formula unit. The energy barrier to the transition from the superstructure to the simple tetragonal structure is 0.24 eV at 7 GPa; thus, high temperatures are required to synthesize the latter. Among the possible structural configurations resulting from the partially occupied oxygen site in the superstructure phase, the most stable structure has a space group PN4m2, reduced from that of the simple tetragonal structure P4=mmm. The detailed analysis of the electronic band structures of the simple tetragonal and superstructure phases suggests that the out-of-plane buckling of the O atoms in the superstructure leads to significant decrease in the O p-Cu d orbital overlap, allowing the energy of the system to be lowered, which is necessary for the structural stability. An understanding of the electronic structure and energetics of the high-pressure superstructure phase and its relation to the simple tetragonal phase provides a basis for exploring the physical properties of the infinite layer, high-TC superconductor.

    View details for DOI 10.1088/0953-8984/23/46/465503

    View details for Web of Science ID 000296795400013

    View details for PubMedID 22056857

  • Phase stability of some actinides with brannerite structure at high pressures JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Lang, M., Liu, Z., Ewing, R. C. 2011; 184 (11): 2834-2839
  • Trace metal nanoparticles in pyrite ORE GEOLOGY REVIEWS Deditius, A. P., Utsunomiya, S., Reich, M., Kesler, S. E., Ewing, R. C., Hough, R., Walshe, J. 2011; 42 (1): 32-46
  • Role of iron in the incorporation of uranium in ferric garnet matrices PHYSICAL REVIEW B Rak, Z., Ewing, R. C., Becker, U. 2011; 84 (15)
  • Structural changes of (K,Gd)(2)Ta2O7 pyrochlore at high pressure JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Lang, M., ZHANG, J. M., Ewing, R. C., Nyman, M. 2011; 184 (9): 2329-2332
  • Actinides and radiation effects: impact on the back-end of the nuclear fuel cycle MINERALOGICAL MAGAZINE Ewing, R. C. 2011; 75 (4): 2359-2377
  • Thermodynamic properties of ThxU1-xO2 (0 < x < 1) based on quantum-mechanical calculations and Monte-Carlo simulations JOURNAL OF NUCLEAR MATERIALS Shuller, L. C., Ewing, R. C., Becker, U. 2011; 412 (1): 13-21
  • First-principles investigation of Ca-3(Ti, Zr, Hf, Sn)(2)Fe2SiO12 garnet structure for incorporation of actinides PHYSICAL REVIEW B Rak, Z., Ewing, R. C., Becker, U. 2011; 83 (15)
  • Phase Transformation of Nanosized ZrO2 upon Thermal Annealing and Intense Radiation JOURNAL OF PHYSICAL CHEMISTRY C Lu, F., Zhang, J., Huang, M., Namavar, F., Ewing, R. C., Lian, J. 2011; 115 (15): 7193-7201

    View details for DOI 10.1021/jp109558s

    View details for Web of Science ID 000289403200006

  • Effects of Ionizing Radiation and Temperature on Uranyl Silicates: Soddyite (UO2)(2)(SiO4)(H2O)(2) and Uranophane Ca(UO2)(2)(SiO3OH)(2)center dot 5H(2)O ENVIRONMENTAL SCIENCE & TECHNOLOGY Sureda, R., Casas, I., Gimenez, J., de Pablo, J., Quinones, J., Zhang, J., Ewing, R. C. 2011; 45 (6): 2510-2515

    Abstract

    The stability of soddyite under electron irradiation has been studied over the temperature range of 25-300 °C. At room temperature, soddyite undergoes a crystalline-to-amorphous transformation (amorphization) at a total dose of 6.38 × 10(8) Gy. The electron beam irradiation results suggest that the soddyite structure is susceptible to radiation-induced nanocrystallization of UO(2). The temperature dependence of amorphization dose increases linearly up to 300 °C. A thermogravimetric and calorimetric analysis (TGA-DSC) combined with X-ray diffraction (XRD) indicates that soddyite retains its water groups up to 400 °C, followed by the collapse of the structure. Based on thermal analysis of uranophane, the removal of some water groups at relatively low temperatures provokes the collapse of the uranophane structure. This structural change appears to be the reason for the increase of amorphization dose at 140 °C. According to the results obtained, radiation field of a nuclear waste repository, rather than temperature effects, may cause changes in the crystallinity of soddyite and affect its stability during long-term storage.

    View details for DOI 10.1021/es1041496

    View details for Web of Science ID 000288146200067

    View details for PubMedID 21319815

  • Annealing kinetics of latent particle tracks in Durango apatite PHYSICAL REVIEW B Afra, B., Lang, M., Rodriguez, M. D., Zhang, J., Giulian, R., Kirby, N., Ewing, R. C., Trautmann, C., Toulemonde, M., Kluth, P. 2011; 83 (6)
  • Energetic stability, structural transition, and thermodynamic properties of ZnSnO3 APPLIED PHYSICS LETTERS Gou, H., Zhang, J., Li, Z., Wang, G., Gao, F., Ewing, R. C., Lian, J. 2011; 98 (9)

    View details for DOI 10.1063/1.3562013

    View details for Web of Science ID 000288026700026

  • Thermal annealing mechanisms of latent fission tracks: Apatite vs. zircon EARTH AND PLANETARY SCIENCE LETTERS Li, W., Wang, L., Lang, M., Trautmann, C., Ewing, R. C. 2011; 302 (1-2): 227-235
  • Energetics and concentration of defects in Gd2Ti2O7 and Gd2Zr2O7 pyrochlore at high pressure ACTA MATERIALIA Wang, J., Zhang, F., Lian, J., Ewing, R. C., Becker, U. 2011; 59 (4): 1607-1618
  • Safe management of actinides in the nuclear fuel cycle: Role of mineralogy COMPTES RENDUS GEOSCIENCE Ewing, R. C. 2011; 343 (2-3): 219-229
  • Irradiation of synthetic garnet by heavy ions and alpha-decay of Cm-244 JOURNAL OF NUCLEAR MATERIALS Zhang, J., Livshits, T. S., Lizin, A. A., Hu, Q., Ewing, R. C. 2010; 407 (3): 137-142
  • OH species, U ions, and CO/CO2 in thermally annealed metamict zircon (ZrSiO4) AMERICAN MINERALOGIST Zhang, M., Salje, E. K., Ewing, R. C. 2010; 95 (11-12): 1717-1724
  • Pressure-induced structural transformations in lanthanide titanates: La2TiO5 and Nd2TiO5 JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Wang, J. W., Lang, M., ZHANG, J. M., Ewing, R. C. 2010; 183 (11): 2636-2643
  • The Association Between Community Physical Activity Settings and Youth Physical Activity, Obesity, and Body Mass Index JOURNAL OF ADOLESCENT HEALTH Slater, S. J., Ewing, R., Powell, L. M., Chaloupka, F. J., Johnston, L. D., O'Malley, P. M. 2010; 47 (5): 496-503

    Abstract

    This study examined the association between the level of physical activity (PA) friendliness of the built environment and adolescent PA and body mass index using a national sample of youth and data collected from the communities where they reside.Data on height, weight, and PA were taken from annual nationally representative cross-sectional Monitoring the Future surveys of 8th and 10th graders in schools, from 2001 through 2003. Measures of safety, outdoor and commercial PA settings, and urban sprawl were constructed using data collected from the communities in which the students reside. Multilevel models were run and controlled for youth and community demographic and socioeconomic characteristics.Increased levels of physical disorder were associated with decreased PA and higher weight. A greater number of commercial PA facilities was associated with increased PA. More compact communities were associated with lower weight and less sports participation.It is important to explore these associations to help guide future development patterns and land use policies to create more active neighborhoods.

    View details for DOI 10.1016/j.jadohealth.2010.03.017

    View details for Web of Science ID 000283263100012

    View details for PubMedID 20970085

  • Time-response relationship of nano and micro particle induced lung inflammation. Quartz as reference compound HUMAN & EXPERIMENTAL TOXICOLOGY Roursgaard, M., Poulsen, S. S., Poulsen, L. K., Hammer, M., Jensen, K. A., Utsunomiya, S., Ewing, R. C., Balic-Zunic, T., Nielsen, G. D., Larsen, S. T. 2010; 29 (11): 915-933

    Abstract

    An increasing number of engineered particles, including nanoparticles, are being manufactured, increasing the need for simple low-dose toxicological screening methods. This study aimed to investigate the kinetics of biomarkers related to acute and sub-chronic particle-induced lung inflammation of quartz. Mice were intratracheal instilled with 50 µg of microsized or nanosized quartz. Acute inflammation was assessed 1, 2, 4, 8, 16 or 48 hours post exposure, whereas sub-chronic inflammation was investigated 3 months after exposure. Markers of acute inflammation in the bronchoalveolar lavage fluid (BALF) were neutrophils (PMN), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, macrophage inflammatory protein-2 (MIP-2), keratinocyte derived chemokine (KC) and total protein, which were all close to maximum 16 hours post instillation. No major differences were seen in the time-response profiles of nano- and micro-sized particles. The potency of the two samples cannot be compared; during the milling process, a substantial part of the quartz was converted to amorphous silica and contaminated with corundum. For screening, BALF PMN, either TNF-α or IL-1β at 16 hours post instillation may be useful. At 3 months post instillation, KC, PMN and macrophages were elevated. Histology showed no interstitial inflammation three months post instillation. For screening of sub-chronic effects, KC, PMN, macrophages and histopathology is considered sufficient.

    View details for DOI 10.1177/0960327110363329

    View details for Web of Science ID 000283054100003

    View details for PubMedID 20237177

  • Environmental impact of the nuclear fuel cycle: Fate of actinides MRS BULLETIN Ewing, R. C., Runde, W., Albrecht-Schmitt, T. E. 2010; 35 (11): 859-866
  • Porous fission fragment tracks in fluorapatite PHYSICAL REVIEW B Li, W., Wang, L., Sun, K., Lang, M., Trautmann, C., Ewing, R. C. 2010; 82 (14)
  • Review of A(2)B(2)O(7) pyrochlore response to irradiation and pressure 15th International Conference of the Radiation Effects in Insulators Lang, M., Zhang, F., Zhang, J., Wang, J., Lian, J., Weber, W. J., Schuster, B., Trautmann, C., Neumann, R., Ewing, R. C. ELSEVIER SCIENCE BV. 2010: 2951–59
  • Fluorescent, Superparamagnetic Nanospheres for Drug Storage, Targeting, and Imaging: A Multifunctional Nanocarrier System for Cancer Diagnosis and Treatment ACS NANO Cho, H., Dong, Z., Pauletti, G. M., Zhang, J., Xu, H., Gu, H., Wang, L., Ewing, R. C., Huth, C., Wang, F., Shi, D. 2010; 4 (9): 5398-5404

    Abstract

    For early cancer diagnosis and treatment, a nanocarrier system is designed and developed with key components uniquely structured at nanoscale according to medical requirements. For imaging, quantum dots with emissions in the near-infrared range (∼800 nm) are conjugated onto the surface of a nanocomposite consisting of a spherical polystyrene matrix (∼150 nm) and the internally embedded, high fraction of superparamagnetic Fe(3)O(4) nanoparticles (∼10 nm). For drug storage, the chemotherapeutic agent paclitaxel (PTX) is loaded onto the surfaces of these composite multifunctional nanocarriers by using a layer of biodegradable poly(lactic-co-glycolic acid) (PLGA). A cell-based cytotoxicity assay is employed to verify successful loading of pharmacologically active drug. Cell viability of human, metastatic PC3mm2 prostate cancer cells is assessed in the presence and absence of various multifunctional nanocarrier populations using the MTT assay. PTX-loaded composite nanocarriers are synthesized by conjugating anti-prostate specific membrane antigen (anti-PSMA) for targeting. Specific detection studies of anti-PSMA-conjugated nanocarrier binding activity in LNCaP prostate cancer cells are carried out. LNCaP cells are targeted successfully in vitro by the conjugation of anti-PSMA on the nanocarrier surfaces. To further explore targeting, the nanocarriers conjugated with anti-PSMA are intravenously injected into tumor-bearing nude mice. Substantial differences in fluorescent signals are observed ex vivo between tumor regions treated with the targeted nanocarrier system and the nontargeted nanocarrier system, indicating considerable targeting effects due to anti-PSMA functionalization of the nanocarriers.

    View details for DOI 10.1021/nn101000e

    View details for Web of Science ID 000282121000055

    View details for PubMedID 20707381

  • Quantum-mechanical evaluation of Np-incorporation into studtite AMERICAN MINERALOGIST Shuller, L. C., Ewing, R. C., Becker, U. 2010; 95 (8-9): 1151-1160
  • Amorphization of rare earth aluminate garnets under ion irradiation and decay of Cm-244 admixture GEOLOGY OF ORE DEPOSITS Livshits, T. S., Lizin, A. A., ZHANG, J. M., Ewing, R. C. 2010; 52 (4): 267-278
  • Intrinsic Structural Disorder and Radiation Response of Nanocrystalline Gd-2(Ti0.65Zr0.35)(2)O-7 Pyrochlore JOURNAL OF PHYSICAL CHEMISTRY C Zhang, J., Lian, J., Zhang, F., Wang, J., Fuentes, A. F., Ewing, R. C. 2010; 114 (27): 11810-11815

    View details for DOI 10.1021/jp103371j

    View details for Web of Science ID 000279507900019

  • Nanoscale phase transitions under extreme conditions within an ion track JOURNAL OF MATERIALS RESEARCH Zhang, J., Lang, M., Ewing, R. C., Devanathan, R., Weber, W. J., Toulemonde, M. 2010; 25 (7): 1344-1351
  • Pressure-Induced Disordering and Anomalous Lattice Expansion in La2Zr2O7 Pyrochlore PHYSICAL REVIEW LETTERS Zhang, F. X., Lang, M., Liu, Z., Ewing, R. C. 2010; 105 (1)

    Abstract

    Pressure-induced cation and anion disordering in La2Zr2O7 pyrochlore is quantitatively analyzed by Rietveld refinement of in situ x-ray diffraction patterns, Raman, and infrared measurements. An anomalous lattice expansion and obvious change of the pressure dependence of the vibrational modes occur at ∼10  GPa. The pressure-induced water incorporation in the La2Zr2O7 pyrochlore structure may be related to a previously noted photoelectrochemical effect.

    View details for DOI 10.1103/PhysRevLett.105.015503

    View details for Web of Science ID 000279392600001

    View details for PubMedID 20867461

  • The influence of muscovite and orthoclase on the precipitation of CaCO3 polymorphs Conference on Goldschmidt 2010 - Earth, Energy, and the Environment Hu, Q., Zhang, J., Teng, H., Ewing, R., Becker, U. PERGAMON-ELSEVIER SCIENCE LTD. 2010: A424–A424
  • Electronic structure of Ti, Zr, Hf and Sn containing garnets - Materials for immobilization of actinides Conference on Goldschmidt 2010 - Earth, Energy, and the Environment Rak, Z., Ewing, R. C., Becker, U. PERGAMON-ELSEVIER SCIENCE LTD. 2010: A845–A845
  • U and Th mineral evolution Conference on Goldschmidt 2010 - Earth, Energy, and the Environment Hazen, R. M., Ewing, R. C., Sverjensky, D. A. PERGAMON-ELSEVIER SCIENCE LTD. 2010: A389–A389
  • Increased stability of nanocrystals of Gd-2(Ti0.65Zr0.35)(2)O-7 pyrochlore at high pressure JOURNAL OF ALLOYS AND COMPOUNDS Zhang, F. X., Lian, J., ZHANG, J. M., Moreno, K. J., Fuentes, A. F., Wang, Z., Ewing, R. C. 2010; 494 (1-2): 34-39
  • Precipitation and alteration of coffinite (USiO4 center dot nH(2)O) in the presence of apatite EUROPEAN JOURNAL OF MINERALOGY Deditius, A. P., Utsunomiya, S., Pointeau, V., Ewing, R. C. 2010; 22 (1): 75-88
  • Simulation of thermodynamic mixing properties of actinide-containing zircon solid solutions AMERICAN MINERALOGIST Ferriss, E. D., Ewing, R. C., Becker, U. 2010; 95 (2-3): 229-241
  • Synthetic Minerals with the Pyrochlore and Garnet Structures for Immobilization of Actinide-Containing Wastes GEOCHEMISTRY INTERNATIONAL Laverov, N. P., Yudintsev, S. V., Livshits, T. S., Stefanovsky, S. V., Lukinykh, A. N., Ewing, R. C. 2010; 48 (1): 1-14
  • FLUORESCENT SUPER PARAMAGNETIC NANOPARTICLES FOR MEDICAL DIAGNOSIS AND TREATMENT 3rd IEEE International NanoElectronics Conference (INEC)/Symposium on Nanoscience and Nanotechnology in China Shi, D., Cho, H. S., Huth, C., Xu, H., Gu, H. C., Pauletti, G. M., Dong, Z. Y., Lian, J., Ewing, R. C. IEEE. 2010: 350–351
  • Zirconate pyrochlores under high pressure PHYSICAL CHEMISTRY CHEMICAL PHYSICS Xiao, H. Y., Zhang, F. X., Gao, F., Lang, M., Ewing, R. C., Weber, W. J. 2010; 12 (39): 12472-12477

    Abstract

    Ab initio total-energy calculations and X-ray diffraction measurements have been combined to study the phase stability of zirconate pyrochlores (A(2)Zr(2)O(7); A = La, Nd and Sm) under pressures up to 50 GPa. Phase transformations to the defect-cotunnite structure are theoretically predicted at pressures of 22, 20 and 18 GPa, in excellent agreement with the experimentally determined values of 21, 22 and 18 GPa for La(2)Zr(2)O(7), Nd(2)Zr(2)O(7) and Sm(2)Zr(2)O(7), respectively. Analysis of the elastic properties indicates that elastic anisotropy may be one of the driving forces for the pressure-induced cubic-to-noncubic phase transformation.

    View details for DOI 10.1039/c0cp00278j

    View details for Web of Science ID 000282643900015

    View details for PubMedID 20721363

  • Political Pressure's Effect on Repository Sites Response SCIENCE Ewing, R. C., von Hippel, F. N. 2009; 326 (5959): 1480-1480
  • ELEMENTS' FIFTH ANNIVERSARY ELEMENTS Ewing, R. C. 2009; 5 (6): 343-343
  • Conjugation of quantum dots and Fe3O4 on carbon nanotubes for medical diagnosis and treatment APPLIED PHYSICS LETTERS Shi, D., Cho, H. S., Huth, C., Wang, F., Dong, Z., Pauletti, G. M., Lian, J., Wang, W., Liu, G., Bud'ko, S. L., Wang, L., Ewing, R. C. 2009; 95 (22)

    View details for DOI 10.1063/1.3268469

    View details for Web of Science ID 000272627600083

  • High-pressure phase transitions of ScPO4 and YPO4 PHYSICAL REVIEW B Zhang, F. X., Wang, J. W., Lang, M., ZHANG, J. M., Ewing, R. C., Boatner, L. A. 2009; 80 (18)
  • Chemical and structural characterization of As immobilization by nanoparticles of mackinawite (FeSm) CHEMICAL GEOLOGY Renock, D., Gallegos, T., Utsunomiya, S., Hayes, K., Ewing, R. C., Becker, U. 2009; 268 (1-2): 116-125
  • Nanoscale manipulation of the properties of solids at high pressure with relativistic heavy ions NATURE MATERIALS Lang, M., Zhang, F., Zhang, J., Wang, J., Schuster, B., Trautmann, C., Neumann, R., Becker, U., Ewing, R. C. 2009; 8 (10): 793-797

    Abstract

    High-pressure and high-temperature phases show unusual physical and chemical properties, but they are often difficult to 'quench' to ambient conditions. Here, we present a new approach, using bombardment with very high-energy, heavy ions accelerated to relativistic velocities, to stabilize a high-pressure phase. In this case, Gd(2)Zr(2)O(7), pressurized in a diamond-anvil cell up to 40 GPa, was irradiated with 20 GeV xenon or 45 GeV uranium ions, and the (previously unquenchable) cubic high-pressure phase was recovered after release of pressure. Transmission electron microscopy revealed a radiation-induced, nanocrystalline texture. Quantum-mechanical calculations confirm that the surface energy at the nanoscale is the cause of the remarkable stabilization of the high-pressure phase. The combined use of high pressure and high-energy ion irradiation provides a new means for manipulating and stabilizing new materials to ambient conditions that otherwise could not be recovered.

    View details for DOI 10.1038/NMAT2528

    View details for Web of Science ID 000270075600012

    View details for PubMedID 19734884

  • Evolution of uranium and thorium minerals AMERICAN MINERALOGIST Hazen, R. M., Ewing, R. C., Sverjensky, D. A. 2009; 94 (10): 1293-1311
  • Synthesis and characterization of coffinite JOURNAL OF NUCLEAR MATERIALS Pointeau, V., Deditius, A. P., Miserque, F., Renock, D., Becker, U., Zhang, J., Clavier, N., Dacheux, N., Poinssot, C., Ewing, R. C. 2009; 393 (3): 449-458
  • Response of synthetic coffinite to energetic ion beam irradiation JOURNAL OF NUCLEAR MATERIALS Lian, J., ZHANG, J. M., Pointeau, V., Zhang, F. X., Lang, M., Lu, F. Y., Poinssot, C., Ewing, R. C. 2009; 393 (3): 481-486
  • High-Pressure Response of Zirconia Nanoparticles with an Alumina Shell JOURNAL OF PHYSICAL CHEMISTRY C Zhang, F. X., Lang, M., Ewing, R. C., Lian, J., Wang, Z. W. 2009; 113 (33): 14658-14662

    View details for DOI 10.1021/jp904144y

    View details for Web of Science ID 000268907500014

  • Decoupled geochemical behavior of As and Cu in hydrothermal systems GEOLOGY Deditius, A. P., Utsunomiya, S., Ewing, R. C., Chryssoulis, S. L., Venter, D., Kesler, S. E. 2009; 37 (8): 707-710

    View details for DOI 10.1130/G25781A.1

    View details for Web of Science ID 000268498600009

  • Propagation of ripples on pyrochlore induced by ion beam bombardment PHYSICAL REVIEW B Wei, Q., Lian, J., Boatner, L. A., Wang, L. M., Ewing, R. C. 2009; 80 (8)
  • Nuclear Waste Management in the United States-Starting Over SCIENCE Ewing, R. C., von Hippel, F. N. 2009; 325 (5937): 151-152

    View details for DOI 10.1126/science.1174594

    View details for Web of Science ID 000267802000028

    View details for PubMedID 19589986

  • Radiation Response of Nanocrystalline Rutile (TiO2) Zhang, J., Lian, J., Namavar, F., Ewing, R. C. CAMBRIDGE UNIV PRESS. 2009: 1366–1367
  • Effects of electron and ion irradiation on the annealing behavior of fission tracks and the microstructure of fluorapatite Li, W. X., Sun, K., Wei, Q. M., Lang, M., Wang, L. M., Ewing, R. C. CAMBRIDGE UNIV PRESS. 2009: 1354–1355
  • Radiation Response of Nanostructured Pyrochlore and Zirconia Lian, J., Zhang, J., Fuentes, A. F., Namavar, F., Ewing, R. C. CAMBRIDGE UNIV PRESS. 2009: 1338–1339
  • Structural transitions and electron transfer in coffinite, USiO4, at high pressure AMERICAN MINERALOGIST Zhang, F. X., Pointeau, V., Shuller, L. C., Reaman, D. M., Lang, M., Liu, Z., Hu, J., Panero, W. R., Becker, U., Poinssot, C., Ewing, R. C. 2009; 94 (7): 916-920
  • Ion beam-induced amorphous-to-tetragonal phase transformation and grain growth of nanocrystalline zirconia NANOTECHNOLOGY Lian, J., Zhang, J., Namavar, F., Zhang, Y., Lu, F., Haider, H., Garvin, K., Weber, W. J., Ewing, R. C. 2009; 20 (24)

    Abstract

    Nanocrystalline zirconia has recently attracted extensive research interest due to its unique mechanical, thermal and electrical properties as compared with bulk zirconia counterparts, and it is of particular importance for controlling the phase stability of different polymorphs (amorphous, cubic, tetragonal and monoclinic phases) in different size regimes. In this work, we performed ion beam bombardments on bilayers (amorphous and cubic) of nano-zirconia using 1 MeV Kr2+ irradiation. Transmission electron microscopy (TEM) analysis reveals that amorphous zirconia transforms to a tetragonal structure under irradiation at room temperature, suggesting that the tetragonal phase is more energetically favorable under these conditions. The final grain size of the tetragonal zirconia can be controlled by irradiation conditions. A slower kinetics in the grain growth from cubic nanocrystalline zirconia was found as compared with that for the tetragonal grains recrystallized from the amorphous layer. The radiation-induced nanograins of tetragonal ZrO2 are stable at ambient conditions and maintain their physical integrity over a long period of time after irradiation. These results demonstrated that ion beam methods provide the means to control the phase stability and structure of zirconia polymorphs.

    View details for DOI 10.1088/0957-4484/20/24/245303

    View details for Web of Science ID 000266436500009

    View details for PubMedID 19468161

  • Enhanced radiation resistance of nanocrystalline pyrochlore Gd-2(Ti0.65Zr0.35)(2)O-7 APPLIED PHYSICS LETTERS Zhang, J., Lian, J., Fuentes, A. F., Zhang, F., Lang, M., Lu, F., Ewing, R. C. 2009; 94 (24)

    View details for DOI 10.1063/1.3155855

    View details for Web of Science ID 000267166600067

  • Fluorescent Polystyrene-Fe3O4 Composite Nanospheres for In Vivo Imaging and Hyperthermia ADVANCED MATERIALS Shi, D., Cho, H. S., Chen, Y., Xu, H., Gu, H., Lian, J., Wang, W., Liu, G., Huth, C., Wang, L., Ewing, R. C., Budko, S., Pauletti, G. M., Dong, Z. 2009; 21 (21): 2170-?
  • Single-ion tracks in Gd2Zr2-xTixO7 pyrochlores irradiated with swift heavy ions PHYSICAL REVIEW B Lang, M., Lian, J., Zhang, J., Zhang, F., Weber, W. J., Trautmann, C., Ewing, R. C. 2009; 79 (22)
  • Liquid-like phase formation in Gd2Zr2O7 by extremely ionizing irradiation JOURNAL OF APPLIED PHYSICS Zhang, J., Lang, M., Lian, J., Liu, J., Trautmann, C., Della-Negra, S., Toulemonde, M., Ewing, R. C. 2009; 105 (11)

    View details for DOI 10.1063/1.3124370

    View details for Web of Science ID 000267053200043

  • MgO-pyrochlore composite as an inert matrix fuel: Neutronic and thermal characteristics JOURNAL OF NUCLEAR MATERIALS Imaura, A., Touran, N., Ewing, R. C. 2009; 389 (3): 341-350
  • Response of strontium titanate to ion and electron irradiation Symposium on Particle Beam Induced Radiation Effects in Materials held at the Annual Meeting of the Mineral-Metals-and-Materials-Society Zhang, Y., Lian, J., Zhu, Z., Bennett, W. D., Saraf, L. V., Rausch, J. L., Hendricks, C. A., Ewing, R. C., Weber, W. J. ELSEVIER SCIENCE BV. 2009: 303–10
  • Crystal chemistry and radiation-induced amorphization of P-coffinite from the natural fission reactor at Bangombe, Gabon AMERICAN MINERALOGIST Deditius, A. P., Utsunomiya, S., Wall, M. A., Pointeau, V., Ewing, R. C. 2009; 94 (5-6): 827-836
  • Pb+ irradiation of synthetic zircon (ZrSiO4): Infrared spectroscopic investigation-Reply AMERICAN MINERALOGIST Zhang, M., Ewing, R. C., Boatner, L. A., Salje, E. K., Weber, W. J., Daniel, P., Zhang, Y., Farnan, I. 2009; 94 (5-6): 856-858
  • Structural modifications of Gd2Zr2-xTixO7 pyrochlore induced by swift heavy ions: Disordering and amorphization JOURNAL OF MATERIALS RESEARCH Lang, M., Zhang, F. X., Ewing, R. C., Lian, J., Trautmann, C., Wang, Z. 2009; 24 (4): 1322-1334
  • Source-to-receptor pathways of anthropogenic PM2.5 in Detroit, Michigan: Comparison of two inhalation exposure studies ATMOSPHERIC ENVIRONMENT Morishita, M., Keeler, G. J., McDonald, J. D., Wagner, J. G., Young, L., Utsunomiya, S., Ewing, R. C., Harkema, J. R. 2009; 43 (10): 1805-1813
  • Groundwater Nanoparticles in the Far-Field at the Nevada Test Site: Mechanism for Radionuclide Transport ENVIRONMENTAL SCIENCE & TECHNOLOGY Utsunomiya, S., Kersting, A. B., Ewing, R. C. 2009; 43 (5): 1293-1298

    Abstract

    Colloid-like nanoparticles in groundwater have been shown to facilitate migration of several radionuclides: (239,240)Pu, 137Cs, (152,154, 155)Eu, and 60Co. However, the exact type of nanoparticle and the speciation of the associated radionuclides has remained unknown. We have investigated nanoparticles sampled from the far-field at the Nevada Test Site, Nevada, utilizing advanced electron microscopytechniques, including high-angle annular dark-field scanning TEM (HAADF-STEM). Fissiogenic elements: Cs, rare earth elements (REE), activation elements: Co; and actinides: U and Th, were detected. Cesium is associated with U-forming cesium uranate with a Cs/U atomic ratio of approximately 0.12. Light REEs and Th are associated with phosphates, silicates, or apatite. Cobalt occurs as a metallic aggregate, associated with Cr, Fe, Ni, and +/-Mo. Uranyl minerals; Na-boltwoodite and oxide hydrates are also present as colloids. Because of these chemical associations with nanoscale particles, in the size range <100 nm, these particles may facilitate transport, and a variety of trace nanoscale phases may be responsible for the migration of fissiogenic and actinide elements in groundwater. To accurately model the transport of these contaminants, predictive transport models should include consideration of nanoparticle-facilitated transport.

    View details for DOI 10.1021/es802181t

    View details for Web of Science ID 000263758600013

    View details for PubMedID 19350893

  • In Situ TEM of Radiation Effects in Complex Ceramics MICROSCOPY RESEARCH AND TECHNIQUE Lian, J., Wang, L. M., Sun, K., Ewing, R. C. 2009; 72 (3): 165-181

    Abstract

    In situ transmission electron microscopy (TEM) has been extensively applied to study radiation effects in a wide variety of materials, such as metals, ceramics and semiconductors and is an indispensable tool in obtaining a fundamental understanding of energetic beam-matter interactions, damage events, and materials' behavior under intense radiation environments. In this article, in situ TEM observations of radiation effects in complex ceramics (e.g., oxides, silicates, and phosphates) subjected to energetic ion and electron irradiations have been summarized with a focus on irradiation-induced microstructural evolution, changes in microchemistry, and the formation of nanostructures. New results for in situ TEM observation of radiation effects in pyrochlore, A(2)B(2)O(7), and zircon, ZrSiO(4), subjected to multiple beam irradiations are presented, and the effects of simultaneous irradiations of alpha-decay and beta-decay on the microstructural evolution of potential nuclear waste forms are discussed. Furthermore, in situ TEM results of radiation effects in a sodium borosilicate glass subjected to electron-beam exposure are introduced to highlight the important applications of advanced analytical TEM techniques, including Z-contrast imaging, energy filtered TEM (EFTEM), and electron energy loss spectroscopy (EELS), in studying radiation effects in materials microstructural evolution and microchemical changes. By combining ex situ TEM and advanced analytical TEM techniques with in situ TEM observations under energetic beam irradiations, one can obtain invaluable information on the phase stability and response behaviors of materials under a wide range of irradiation conditions.

    View details for DOI 10.1002/jemt.20669

    View details for Web of Science ID 000264238500006

    View details for PubMedID 19130508

  • UO2 corrosion in an iron waste package JOURNAL OF NUCLEAR MATERIALS Ferriss, E. D., Helean, K. B., Bryan, C. R., Brady, P. V., Ewing, R. C. 2009; 384 (2): 130-139
  • Surface charge induced Stark effect on luminescence of quantum dots conjugated on functionalized carbon nanotubes CHEMICAL PHYSICS LETTERS Wang, W., Liu, G. K., Cho, H. S., Guo, Y., Shi, D., Lian, J., Ewing, R. C. 2009; 469 (1-3): 149-152
  • Stability of uranium (VI) peroxide hydrates under ionizing radiation AMERICAN MINERALOGIST Rey, A., Utsunomiya, S., Gimenez, J., Casas, I., De Pablo, J., Ewing, R. C. 2009; 94 (2-3): 229-235
  • Nanoscale "liquid" inclusions of As-Fe-S in arsenian pyrite AMERICAN MINERALOGIST Deditius, A. P., Utsunomiya, S., Ewing, R. C., Kesler, S. E. 2009; 94 (2-3): 391-394
  • LOST IN TRANSLATION ELEMENTS Ewing, R. 2009; 5 (1): 5-6
  • Thermodynamic Properties of Actinide-Oxide Solid-Solutions Symposium on Materials for Future Fusion and Fission Technologies held at the 2008 MRS Fall Meeting Shuller, L. C., Pavenayotin, N., Ewing, R. C., Becker, U. MATERIALS RESEARCH SOCIETY. 2009: 95–100
  • UO2 Corrosion in an Iron Waste Package 32nd Symposium on Scientific Basis for Nuclear Waste Management held at the 2008 MRS Fall Meeting Ferriss, E. D., Helean, K. B., Bryan, C. R., Brady, P. V., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2009: 105–110
  • Radiation-Stability of Smectite ENVIRONMENTAL SCIENCE & TECHNOLOGY Sorieul, S., Allard, T., Wang, L. M., Grambin-Lapeyre, C., Lian, J., Calas, G., Ewing, R. C. 2008; 42 (22): 8407-8411

    Abstract

    The safety assessment of geological repositories for high-level nuclear waste and spent nuclear fuel requires an understanding of the response of materials to high temperatures and intense radiation fields. Clays, such as smectite, have been proposed as backfill material around waste packages, but their response to intense radiation from short-lived fission products and alpha decay of sorbed actinides remains poorly understood. Cumulative doses may amorphize clays and may alter their properties of sorption, swelling, or water retention. We describe the amorphization of smectites induced by electron and heavy ion irradiations to simulate ionizing radiation and alpha recoil nuclei, respectively. A new "bell-shaped" evolution of the amorphization dose with temperature has been determined. The maximum dose for amorphization occurs at about 300-400 degrees C, showing that temperature-induced dehydroxylation enhances amorphization. The exact shape of the bell-shaped curves depends on the interlayer cation. At ambient temperature, ionizing radiation and alpha-decay events do not show the same efficiency. The former results in amorphization at doses between 10(10)-10(11) Gy which are greater than the total radiation dose expected for radioactive waste over 10(6) years. In contrast, alpha-decay events amorphize clays at doses as low as 0.13-0.16 displacements per atom, i.e. doses consistent with nuclear waste accumulated over approximately 1000 yrs. However, the limited penetration of alpha particles and recoil nuclei, in the 100 nm - 20 microm range, will minimize damage. Clays will not be amorphized unless the waste package is breached and released actinides are heavily sorbed onto the clay overpack.

    View details for DOI 10.1021/es800766b

    View details for Web of Science ID 000260921400038

    View details for PubMedID 19068825

  • Fission tracks simulated by swift heavy ions at crustal pressures and temperatures EARTH AND PLANETARY SCIENCE LETTERS Lang, M., Lian, J., Zhang, F., Hendriks, B. W., Trautmann, C., Neumann, R., Ewing, R. C. 2008; 274 (3-4): 355-358
  • Enhanced thermal stability of carbon nanotubes by plasma surface modification in Al2O3 composites JOURNAL OF APPLIED PHYSICS Cho, H., Shi, D., Guo, Y., Lian, J., Ren, Z., Poudel, B., Song, Y., Abot, J. L., Singh, D., Routbort, J., Wang, L., Ewing, R. C. 2008; 104 (7)

    View details for DOI 10.1063/1.2985915

    View details for Web of Science ID 000260125500120

  • Pressure-induced zircon-type to scheelite-type phase transitions in YbPO4 and LuPO4 JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Lang, M., Ewing, R. C., Lian, J., Wang, Z. W., Hu, J., Boatner, L. A. 2008; 181 (10): 2633-2638
  • In vivo imaging and drug storage by quantum-dot-conjugated carbon nanotubes ADVANCED FUNCTIONAL MATERIALS Guo, Y., Shi, D., Cho, H., Dong, Z., Kulkarni, A., Pauletti, G. M., Wang, W., Lian, J., Liu, W., Ren, L., Zhang, Q., Liu, G., Huth, C., Wang, L., Ewing, R. C. 2008; 18 (17): 2489-2497
  • Pb+ irradiation of synthetic zircon (ZrSiO4): Infrared spectroscopic investigation AMERICAN MINERALOGIST Zhang, M., Boatner, L. A., Salje, E. K., Honda, S., Ewing, R. C. 2008; 93 (8-9): 1418-1423
  • Structural phase transitions of cubic Gd2O3 at high pressures PHYSICAL REVIEW B Zhang, F. X., Lang, M., Wang, J. W., Becker, U., Ewing, R. C. 2008; 78 (6)
  • Museums are not attics ELEMENTS Ewing, R. C. 2008; 4 (4): 221-222
  • Actinide adsorption onto hematite (001) surface 18th Annual V M Goldschmidt Conference Shuller, L. C., Poling, J., Ewing, R. C., Becker, U. PERGAMON-ELSEVIER SCIENCE LTD. 2008: A864–A864
  • Gold deposition onto arsenian pyrite 18th Annual V M Goldschmidt Conference Renock, D., Deditius, A., Reich, A., Kesler, S. E., Ewing, R. C., Becker, U. PERGAMON-ELSEVIER SCIENCE LTD. 2008: A788–A788
  • Horizontally aligned Cu5Si polycrystalline nanorods on Si APPLIED PHYSICS LETTERS Wu, W., Yu, Q., Zhang, J., Lian, J., Liang, G., Ewing, R. C., Pei, S. 2008; 92 (25)

    View details for DOI 10.1063/1.2952770

    View details for Web of Science ID 000257231200064

  • A proposed new type of arsenian pyrite: Composition, nanostructure and geological significance GEOCHIMICA ET COSMOCHIMICA ACTA Deditius, A. P., Utsunomiya, S., Renock, D., Ewing, R. C., Ramana, C. V., Becker, U., Kesler, S. E. 2008; 72 (12): 2919-2933
  • The chemical stability of coffinite, USiO4 center dot nH(2)O; 0 < n < 2, associated with organic matter: A case study from Grants uranium region, New Mexico, USA CHEMICAL GEOLOGY Deditius, A. P., Utsunomiya, S., Ewing, R. C. 2008; 251 (1-4): 33-49
  • Fabrication of nano-/micro-patterns on iron phosphate glass surfaces by focused energetic beams 14th International Conference on Radiation Effects in Insulators (REI-14) Sun, K., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2008: 3133–37
  • Structural and bonding properties of stannate pyrochlores: A density functional theory investigation COMPUTATIONAL MATERIALS SCIENCE Chen, Z. J., Xiao, H. Y., Zu, X. T., Wang, L. M., Gao, F., Lian, J., Ewing, R. C. 2008; 42 (4): 653-658
  • Irradiation-induced stabilization of zircon (ZrSiO4) at high pressure EARTH AND PLANETARY SCIENCE LETTERS Lang, M., Zhang, F., Lian, J., Trautmann, C., Neumann, R., Ewing, R. C. 2008; 269 (1-2): 291-295
  • Self-assembly of well-aligned 3C-SiC ripples by focused ion beam APPLIED PHYSICS LETTERS Zhang, J., Wei, Q., Lian, J., Jiang, W., Weber, W. J., Ewing, R. C. 2008; 92 (19)

    View details for DOI 10.1063/1.2927473

    View details for Web of Science ID 000256564200078

  • Corrosion of UO2 and ThO2: A quantum-mechanical investigation JOURNAL OF NUCLEAR MATERIALS Skomurski, F. N., Shuller, L. C., Ewing, R. C., Becker, U. 2008; 375 (3): 290-310
  • Quantum dot conjugated hydroxylapatite nanoparticles for in vivo imaging NANOTECHNOLOGY Guo, Y., Shi, D., Lian, J., Dong, Z., Wang, W., Cho, H., Liu, G., Wang, L., Ewing, R. C. 2008; 19 (17)

    Abstract

    Hydroxylapatite (HA) nanoparticles were conjugated with quantum dots (QDs) for in vivo imaging. The surface structures of HA nanoparticles with conjugated quantum dots (HA-QD) were studied by transmission electron microscopy (TEM) and laser fluorescent spectroscopy. The TEM data showed that the quantum dots were well conjugated on the HA nanoparticle surfaces. The laser fluorescent spectroscopy results indicated that the HA-QD exhibited promising luminescent emission in vitro. The initial in vivo experiments revealed clear images of HA-QD from the hypodermic injected area at the emission of 600 nm. Furthermore, the optimized in vivo images of HA-QD with near-infrared emission at 800 nm were visualized after intravenous injection. These luminescent HA-QD nanoparticles may find important applications as biodegradable substrates for biomarkers and in drug delivery.

    View details for DOI 10.1088/0957-4484/19/17/175102

    View details for Web of Science ID 000254329700002

    View details for PubMedID 21825660

  • Nuclear fuel cycle: Environmental impact MRS BULLETIN Ewing, R. C. 2008; 33 (4): 338-340
  • Micro-Raman and micro-infrared spectroscopic studies of Pb- and Au-irradiated ZrSiO4: Optical properties, structural damage, and amorphization PHYSICAL REVIEW B Zhang, M., Boatner, L. A., Salje, E. K., Ewing, R. C., Daniel, P., Weber, W. J., Zhang, Y., Farnan, I. 2008; 77 (14)
  • Phase stability and pressure dependence of defect formation in Gd2Ti2O7 and Gd2Zr2O7 pyrochlores PHYSICAL REVIEW LETTERS Zhang, F. X., Wang, J. W., Lian, J., Lang, M. K., Becker, U., Ewing, R. C. 2008; 100 (4)

    Abstract

    We report dramatically different behaviors between isostructural Gd2Ti2O7 and Gd2Zr2O7 pyrochlore at pressures up to 44 GPa, in which the substitution of Ti for Zr significantly increases structural stability. Upon release of pressure, the Gd2Ti2O7 becomes amorphous. In contrast, the high-pressure phase of Gd2Zr2O7 transforms to a disordered defect-fluorite structure. First-principle calculations for both compositions revealed that the response of pyrochlore to high pressure is controlled by the intrinsic energetics of defect formation.

    View details for DOI 10.1103/PhysRevLett.100.045503

    View details for Web of Science ID 000252863400055

    View details for PubMedID 18352296

  • Spectroscopic ellipsometry characterization of the optical properties and thermal stability of ZrO2 films made by ion-beam assisted deposition APPLIED PHYSICS LETTERS Ramana, C. V., Utsunomiya, S., Ewing, R. C., Becker, U., Atuchin, V. V., Aliev, V. S., Kruchinin, V. N. 2008; 92 (1)

    View details for DOI 10.1063/1.2811955

    View details for Web of Science ID 000252284200055

  • High pressure phase transitions and compressibilities of Er2Zr2O7 and Ho2Zr2O7 APPLIED PHYSICS LETTERS Zhang, F. X., Lang, M., Becker, U., Ewing, R. C., Lian, J. 2008; 92 (1)

    View details for DOI 10.1063/1.2830832

    View details for Web of Science ID 000252284200047

  • Np-incorporation into K-boltwoodite 31st Symposium on Scientific Basis for Nuclear Waste Management Shuller, L. C., Ewing, R. C., Becker, U. MATERIALS RESEARCH SOCIETY. 2008: 455–463
  • Effects of ionizing radiation on the hollandite structure-type: Ba0.85Cs0.26Al1.35Fe0.77Ti5.90O16 AMERICAN MINERALOGIST Abdelouas, A., Utsunomiya, S., Suzuki, T., Grambow, B., Advocat, T., Bart, F., Ewing, R. C. 2008; 93 (1): 241-247
  • Waste package corrosion studies using small mockup experiments 31st Symposium on Scientific Basis for Nuclear Waste Management Anderson, B. E., Helean, K. B., Bryan, C. R., Brady, P. V., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2008: 519–526
  • Effects of plasma surface modification on interfacial behaviors and mechanical properties of carbon nanotube-Al2O3 nanocomposites APPLIED PHYSICS LETTERS Guo, Y., Cho, H., Shi, D., Lian, J., Song, Y., Abot, J., Poudel, B., Ren, Z., Wang, L., Ewing, R. C. 2007; 91 (26)

    View details for DOI 10.1063/1.2824865

    View details for Web of Science ID 000251987400011

  • High-pressure structural changes in the Gd2Zr2O7 pyrochlore PHYSICAL REVIEW B Zhang, F. X., Lian, J., Becker, U., Ewing, R. C., Hu, J., Saxena, S. K. 2007; 76 (21)
  • Quantum-dot-activated luminescent carbon nanotubes via a nano scale surface functionalization for in vivo imaging ADVANCED MATERIALS Shi, D., Guo, Y., Dong, Z., Lian, J., Wang, W., Liu, G., Wang, L., Ewing, R. C. 2007; 19 (22): 4033-?
  • Dissolution of radiation-damaged zircon in lateritic soils AMERICAN MINERALOGIST Delattre, S., Utsunomiya, S., Ewing, R. C., Boeglin, J., Braun, J., Balan, E., Calas, G. 2007; 92 (11-12): 1978-1989
  • Fate of trace elements during alteration of uraninite in a hydrothermal vein-type U-deposit from Marshall Pass, Colorado, USA GEOCHIMICA ET COSMOCHIMICA ACTA Deditius, A. P., Utsunomiya, S., Ewing, R. C. 2007; 71 (20): 4954-4973
  • Alteration of UO2+x under oxidizing conditions, Marshall Pass, Colorado, USA 4th Topical Conference on Plutonium and Actinides/Plutonium Futures - The Science 2006 Deditius, A. P., Utsunomiya, S., Ewing, R. C. ELSEVIER SCIENCE SA. 2007: 584–589
  • Ion beam irradiation of U-, Th- and Ce-doped pyrochlores 4th Topical Conference on Plutonium and Actinides/Plutonium Futures - The Science 2006 Lian, J., Yudintsev, S. V., Stefanovsky, S. V., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE SA. 2007: 429–433
  • First-principles study of electronic properties of La2Hf2O7 and Gd2Hf2O7 JOURNAL OF APPLIED PHYSICS Li, N., Xiao, H. Y., Zu, X. T., Wang, L. M., Ewing, R. C., Lian, J., Gao, F. 2007; 102 (6)

    View details for DOI 10.1063/1.2779262

    View details for Web of Science ID 000249787200057

  • Theoretical investigation of structural, energetic and electronic properties of titanate pyrochlores JOURNAL OF PHYSICS-CONDENSED MATTER Xiao, H. Y., Wang, L. M., Zu, X. T., Lian, J., Ewing, R. C. 2007; 19 (34)
  • Arsenic uptake and release on sulfide nanoparticles 17th Annual V M Goldschmidt Conference Renock, D., Utsunomiya, S., Gallegos, T. J., Hayes, K. F., Ewing, R. C., Becker, U. PERGAMON-ELSEVIER SCIENCE LTD. 2007: A833–A833
  • Adsorption energy trends on UO2 and ThO2 surfaces 17th Annual V M Goldschmidt Conference Skomurski, F. N., Ewing, R. C., Becker, U. PERGAMON-ELSEVIER SCIENCE LTD. 2007: A945–A945
  • Structural distortions and phase transformations in Sm2Zr2O7 pyrochlore at high pressures CHEMICAL PHYSICS LETTERS Zhang, F. X., Lian, J., Becker, U., Wang, L. M., Hu, J., Saxena, S., Ewing, R. C. 2007; 441 (4-6): 216-220
  • Low-temperature anisotropic diffusion of helium in zircon: Implications for zircon (U-Th)/He thermochronometry GEOCHIMICA ET COSMOCHIMICA ACTA Reich, M., Ewing, R. C., Ehlers, T. A., Becker, U. 2007; 71 (12): 3119-3130
  • Nuclear materials and materials for fusion - Proceedings of the E-MRS 2006 Spring Meeting: Symposium N on Nuclear Materials and Materials for Fusion - Nice, France - 29 May-2 June 2006 - Editorial note JOURNAL OF NUCLEAR MATERIALS Degueldre, C., Poinssot, C., Ewing, R., Zhou, L. 2007; 362 (2-3): VII-VIII
  • Ion beam irradiation of lanthanum and thorium-doped yttrium titanates Symposium on Nuclear Materials and Materials for Fusion held at the E-MRS 2006 Spring Meeting Lian, J., Zhang, F. X., Peters, M. T., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2007: 438–44
  • Behavior of implanted strontium in yttria-stabilized zirconia APPLIED PHYSICS LETTERS Zhu, S., Wang, S. X., Wang, L. M., Ewing, R. C., Zu, X. T. 2007; 90 (17)

    View details for DOI 10.1063/1.2713127

    View details for Web of Science ID 000246568600040

  • Growth and surface characterization of sputter-deposited molybdenum oxide thin films APPLIED SURFACE SCIENCE Ramana, C. V., Atuchin, V. V., Kesler, V. G., Kochubey, V. A., Pokrovsky, L. D., Shutthanandan, V., Becker, U., Ewing, R. C. 2007; 253 (12): 5368-5374
  • Low-energy Ar+ ion-beam-induced amorphization and chemical modification of potassium titanyl arsenate (001) crystal surfaces JOURNAL OF PHYSICAL CHEMISTRY C Ramana, C. V., Atuchin, V. V., Becker, U., Ewing, R. C., Isaenko, L. I., Khyzhun, O. Y., Merkulov, A. A., Pokrovsky, L. D., Sinelnichenko, A. K., Zhurkov, S. A. 2007; 111 (6): 2702-2708

    View details for DOI 10.1021/jp0671392

    View details for Web of Science ID 000245005700050

  • Structural change of layered perovskite La2Ti2O7 at high pressures JOURNAL OF SOLID STATE CHEMISTRY Zhang, F. X., Lian, J., Becker, U., Ewing, R. C., Wang, L. M., Hu, J., Saxena, S. K. 2007; 180 (2): 571-576
  • Summertime carbonaceous aerosols collected in the marine boundary layer of the Arctic Ocean JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Xie, Z., Blum, J. D., Utsunomiya, S., Ewing, R. C., Wang, X., Sun, L. 2007; 112 (D2)
  • Enhancement of paramagnetic defects in yttria stabilized zirconia implanted by Cs ion irradiation JOURNAL OF ALLOYS AND COMPOUNDS Zu, X. T., Zhu, S., Wang, L. M., Ewing, R. C. 2007; 429 (1-2): 25-28
  • Behavior of Si and C atoms in ion amorphized SiC JOURNAL OF APPLIED PHYSICS Jiang, W., Zhang, Y., Engelhard, M. H., Weber, W. J., Exarhos, G. J., Lian, J., Ewing, R. C. 2007; 101 (2)

    View details for DOI 10.1063/1.2431941

    View details for Web of Science ID 000243890800050

  • Radiation damage and alteration of zircon from a 3.3 Ga porphyritic granite from the Jack Hills, Western Australia CHEMICAL GEOLOGY Utsunomiya, S., Valley, J. W., Cavosie, A. J., Wilde, S. A., Ewing, R. C. 2007; 236 (1-2): 92-111
  • Materials science - Displaced by radiation NATURE Ewing, R. C. 2007; 445 (7124): 161-162

    View details for DOI 10.1038/445161a

    View details for Web of Science ID 000243384300039

    View details for PubMedID 17215837

  • Trace element immobilization by uranyl minerals in granite-hosted uranium ores: Evidences from the Xiazhuang ore field of Guangdong province, China RADIOCHIMICA ACTA Lu, L., Chen, F., Ewing, R. C., Wang, R. 2007; 95 (1): 25-32
  • A science-based approach to understanding waste form durability in open and closed nuclear fuel cycles 30th Symposium on Scientific Basis for Nuclear Waste Management Peters, M. T., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2007: 227–234
  • Np incorporation into uranyl alteration phases: A quantum mechanical approach 30th Symposium on Scientific Basis for Nuclear Waste Management Shuller, L., Ewing, R. C., Becker, U. MATERIALS RESEARCH SOCIETY. 2007: 407–412
  • Perrhenate and pertechnetate Behavior on iron and sulfur-bearing compounds 30th Symposium on Scientific Basis for Nuclear Waste Management Anderson, B. E., Becker, U., Helean, K. B., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2007: 425–430
  • Computational investigation of the formation of hyperstoichiometric uranium dioxide (UO2+x) 30th Symposium on Scientific Basis for Nuclear Waste Management Skomurski, F., Becker, U., Ewing, R. MATERIALS RESEARCH SOCIETY. 2007: 89–94
  • A modular model of the crystal structure of the pyrochlore-murataite polysomatic series CRYSTALLOGRAPHY REPORTS Urusov, V. S., Organova, N. I., Karimova, O. V., Yudintsev, S. V., Ewing, R. C. 2007; 52 (1): 37-46
  • Alteration of coffinite (USiO4) under reducing and oxidizing conditions 30th Symposium on Scientific Basis for Nuclear Waste Management Deditius, A. P., Utsunomiya, S., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2007: 47–52
  • Surface modification of a Ti-Al-Zr alloy by niobium ion implantation SURFACE & COATINGS TECHNOLOGY Zu, X. T., Liu, Y. Z., Lian, J., Liu, H., Wang, Y., Wang, Y. H., Wang, L. M., Ewing, R. C. 2006; 201 (6): 3756-3760
  • The crystal structure of dehydrated wyartite, Ca(CO3)[U5+(U6+O2)(2)O-4(OH)] (H2O)(3) CANADIAN MINERALOGIST Hawthorne, F. C., Finch, R. J., Ewing, R. C. 2006; 44: 1379-1385
  • Thermal behavior of metal nanoparticles in geologic materials GEOLOGY Reich, M., Utsunomiya, S., Kesler, S. E., Wang, L., Ewing, R. C., Becker, U. 2006; 34 (12): 1033-1036
  • Spent nuclear fuel ELEMENTS Bruno, J., Ewing, R. C. 2006; 2 (6): 343-349
  • The nuclear fuel cycle: A role for mineralogy and geochemistry ELEMENTS Ewing, R. C. 2006; 2 (6): 331-334
  • Quantum mechanical vs. empirical potential modeling of uranium dioxide (UO2) surfaces: (111), (110), and (100) AMERICAN MINERALOGIST Skomurski, F. N., Ewing, R. C., Rohl, A. L., Gale, J. D., Becker, U. 2006; 91 (11-12): 1761-1772
  • Pressure-induced structural transitions and phase decomposition in the Cd2Nb2O7 pyrochlore PHYSICAL REVIEW B Zhang, F. X., Lian, J., Becker, U., Ewing, R. C., Wang, L. M., Boatner, L. A., Hu, J., Saxena, S. K. 2006; 74 (17)
  • Luminescent hydroxylapatite nanoparticles by surface functionalization APPLIED PHYSICS LETTERS Wang, W., Shi, D., Lian, J., Guo, Y., Liu, G., Wang, L., Ewing, R. C. 2006; 89 (18)

    View details for DOI 10.1063/1.2374687

    View details for Web of Science ID 000241757500098

  • Colloid transport of plutonium in the far-field of the Mayak Production Association, Russia SCIENCE Novikov, A. P., Kalmykov, S. N., Utsunomiya, S., Ewing, R. C., Horreard, F., Merkulov, A., Clark, S. B., Tkachev, V. V., Myasoedov, B. F. 2006; 314 (5799): 638-641

    Abstract

    Sorption of actinides, particularly plutonium, onto submicrometer-sized colloids increases their mobility, but these plutonium colloids are difficult to detect in the far-field. We identified actinides on colloids in the groundwater from the Mayak Production Association, Urals, Russia; at the source, the plutonium activity is approximately 1000 becquerels per liter. Plutonium activities are still 0.16 becquerels per liter at a distance of 3 kilometers, where 70 to 90 mole percent of the plutonium is sorbed onto colloids, confirming that colloids are responsible for the long-distance transport of plutonium. Nano-secondary ion mass spectrometry elemental maps reveal that amorphous iron oxide colloids adsorb Pu(IV) hydroxides or carbonates along with uranium carbonates.

    View details for DOI 10.1126/science.1131307

    View details for Web of Science ID 000241557800044

    View details for PubMedID 17068260

  • Refinement of the crystal structure of billietite, Ba [(UO2)(6) O-4 (OH)(6)] (H2O)(8) CANADIAN MINERALOGIST Finch, R. J., Burns, P. C., Hawthorne, F. C., Ewing, R. C. 2006; 44: 1197-1205
  • Acceptance of the Dana Medal of the Mineralogical Society of America for 2006 AMERICAN MINERALOGIST Ewing, R. C. 2006; 91 (10): 1712-1713
  • Radiation-induced effects in pyrochlores and nanoscale materials engineering 13th International Conference on Radiation Effects in Insulators (REI-2005) Lian, J., Weber, W. J., Jiang, W., Wang, L. M., Boatner, L. A., Ewing, R. C. ELSEVIER SCIENCE BV. 2006: 128–136
  • XPS and optical studies of Xe+-implanted and annealed YSZ single crystals 13th International Conference on Radiation Effects in Insulators (REI-2005) Xiang, X., Zu, X. T., Zhu, S., Zhang, C. F., Wang, Z. G., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2006: 382–385
  • Irradiation-induced nanostructures in cadmium niobate pyrochlores 13th International Conference on Radiation Effects in Insulators (REI-2005) Jiang, W., Weber, W. J., Young, J. S., Boatner, L. A., Lian, J., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2006: 188–191
  • Perrhenate and pertechnetate behavior on iron and sulfur-bearing compounds 16th Annual V M Goldschmidt Conference Anderson, B. E., Becker, U., Helean, K. B., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2006: A16–A16
  • Adsorbed U(VI) surface species on muscovite identified by laser fluorescence spectroscopy and transmission electron microscopy ENVIRONMENTAL SCIENCE & TECHNOLOGY Arnold, T., Utsunomiya, S., Geipel, G., Ewing, R. C., Baumann, N., Brendler, V. 2006; 40 (15): 4646-4652

    Abstract

    Time-resolved laser-induced fluorescence spectroscopy (TRLFS) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) were applied to investigate the species of uranyl(VI) adsorbed onto muscovite platelets and muscovite suspensions (grain size: 63-200 microm). TRLFS provided evidence for the presence of two adsorbed uranium(VI) surface species on edge-surfaces of muscovite. The two species showed different positions of the fluorescence emission bands and different fluorescence lifetimes indicating a different coordination environment for the two species. HAADF-STEM revealed that nanoclusters of an amorphous uranium phase were attached to the edge-surfaces of muscovite powder during batch sorption experiments. These U-nanoclusters were not observed on {00/} cleavage planes of the muscovite. The surface species with the shorter fluorescence lifetimes are interpreted as truly adsorbed bidentate surface complexes, in which the U(VI) binds to aluminol groups of edge-surfaces. The surface species with the longer fluorescence lifetimes are interpreted to be an amorphous U(VI) condensate or nanosized clusters of polynuclear uranyl(VI) surface species with a particle diameter of 1 to 2 nm. Depending on the size of these clusters the fluorescence lifetimes vary; i.e., the larger the nanosized clusters, the longer is the fluorescence lifetime.

    View details for DOI 10.1021/es0525071

    View details for Web of Science ID 000239437600026

    View details for PubMedID 16913119

  • The mechanisms of reduction of hexavalent chromium by green rust sodium sulphate: Formation of Cr-goethite GEOCHIMICA ET COSMOCHIMICA ACTA Skovbjerg, L. L., Stipp, S. L., Utsunomiya, S., Ewing, R. C. 2006; 70 (14): 3582-3592
  • Direct evidence of N aggregation and diffusion in Au+ irradiated GaN APPLIED PHYSICS LETTERS Jiang, W., Zhang, Y., Weber, W. J., Lian, J., Ewing, R. C. 2006; 89 (2)

    View details for DOI 10.1063/1.2219418

    View details for Web of Science ID 000239793100021

  • Two planets - Which future? ELEMENTS Ewing, R. 2006; 2 (3): 131-131
  • Structural stability and phase transitions in WO3 thin films JOURNAL OF PHYSICAL CHEMISTRY B Ramana, C. V., Utsunomiya, S., Ewing, R. C., Julien, C. M., Becker, U. 2006; 110 (21): 10430-10435

    Abstract

    Tungsten oxide (WO3) thin films have been produced by KrF excimer laser (lambda = 248 nm) ablation of bulk ceramic WO3 targets. The crystal structure, surface morphology, chemical composition, and structural stability of the WO3 thin films have been studied in detail. Characterization of freshly grown WO3 thin films has been performed using X-ray diffraction (XRD), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy (RS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) measurements. The results indicate that the freshly grown WO3 thin films are nearly stoichiometric and well crystallized as monoclinic WO3. The surface morphology of the resulting WO3 thin film has grains of approximately 60 nm in size with a root-mean-square (rms) surface roughness of 10 nm. The phase transformations in the WO3 thin films were investigated by annealing in the TEM column at 30-500 degrees C. The phase transitions in the WO3 thin films occur in sequence as the temperature is increased: monoclinic --> orthorhombic --> hexagonal. Distortion and tilting of the WO6 octahedra occurs with the phase transitions and significantly affects the electronic properties and, hence, the electrochemical device applications of WO3.

    View details for DOI 10.1021/jp056664i

    View details for Web of Science ID 000237844900034

    View details for PubMedID 16722749

  • Patterning metallic nanostructures by ion-beam-induced dewetting and Rayleigh instability NANO LETTERS Lian, J., Wang, L., Sun, X., Yu, Q., Ewing, R. C. 2006; 6 (5): 1047-1052

    View details for DOI 10.1021/nl060492z

    View details for Web of Science ID 000237592900031

  • Deposition of ultrathin rare-earth doped Y2O3 phosphor films on alumina nanoparticles NANOTECHNOLOGY Lian, J., Yang, L., Chen, X. Y., Liu, G. K., Wang, L. M., Ewing, R. C., Shi, D. L. 2006; 17 (5): 1351-1354
  • Simultaneous formation of surface ripples and metallic nanodots induced by phase decomposition and focused ion beam patterning APPLIED PHYSICS LETTERS Lian, J., Zhou, W., Wei, Q. M., Wang, L. M., Boatner, L. A., Ewing, R. C. 2006; 88 (9)

    View details for DOI 10.1063/1.2181203

    View details for Web of Science ID 000235736300078

  • Effect of structure and thermodynamic stability on the response of lanthanide stannate-pyrochlores to ion beam irradiation JOURNAL OF PHYSICAL CHEMISTRY B Lian, J., Helean, K. B., Kennedy, B. J., Wang, L. M., NAVROTSKY, A., Ewing, R. C. 2006; 110 (5): 2343-2350

    Abstract

    The lanthanide stannates, Ln2Sn2O7, Ln=La-Lu and Y, have the isometric pyrochlore structure, A2B2O7, and their structural properties have been refined by Rietveld analysis of powder neutron and synchrotron X-ray diffraction data. In this study, the enthalpies of formation of selected stannate pyrochlores, Ln=La, Nd, Sm, Eu, Dy, and Yb, were measured by high-temperature oxide melt solution calorimetry. Their radiation response was determined by 1 MeV Kr2+ ion irradiation combined with in situ TEM observation over the temperature range of 25 to 1000 K. The enthalpy of formation from binary oxides of stannate pyrochlores became more endothermic (from -145 to -40 kJ/mol) as the size of the lanthanide in the A-site decreases. A more exothermic trend of the enthalpy of formation was observed in stannate pyrochlores with larger lanthanide ions, particularly La, possibly as a result of increased covalency in the Sn-O bond. In contrast to lanthanide titanate pyrochlores, Ln2Ti2O7, that are generally susceptible to radiation-induced amorphization and zirconate pyrochlores, Ln2Zr2O7, that are generally resistant to radiation-induced amorphization, the lanthanide stannate pyrochlores show a much greater variation in their response to ion irradiation. La, Nd, and Gd stannates experience the radiation-induced transformation to the aperiodic state, and the critical amorphization temperatures are approximately 960, 700, and 350 K, respectively. Y and Er stannate pyrochlores cannot be amorphized by ion beam irradiation, even at 25 K, and instead disorder to a defect fluorite structure. Comparison of the calorimetric and ion irradiation data for titanate, zirconate, and stannate pyrochlores reveals a strong correlation among subtle changes in crystal structure with changing composition, the energetics of the disordering process, and the temperature above which the material can no longer be amorphized. In summary, as the structure approaches the ideal, ordered pyrochlore structure, radiation-induced amorphization is more easily attained. This is consistent with an increasingly exothermic trend in the enthalpies of formation of pyrochlores from the oxides, that is, the greater the thermochemical stability of the pyrochlore structure, the more likely it will be amorphized upon radiation damage rather than recover to a disordered fluorite structure.

    View details for DOI 10.1021/jp055266c

    View details for Web of Science ID 000235284300057

    View details for PubMedID 16471823

  • Luminescent carbon nanotubes by surface functionalization ADVANCED MATERIALS Shi, D. L., Lian, J., Wang, W., Liu, G. K., He, P., Dong, Z. Y., Wang, L. M., Ewing, R. C. 2006; 18 (2): 189-?
  • Formation of V2O3 nanocrystals by thermal reduction of V2O5 thin films SOLID STATE COMMUNICATIONS Ramana, C. V., Utsunomiya, S., Ewing, R. C., Becker, U. 2006; 137 (12): 645-649
  • The fate of the epsilon phase (Mo-Ru-Pd-Tc-Rh) in the UO2 of the Oklo natural fission reactors 10th International Conference on Chemistry and Migration of Actinides and Fission Products Utsunomiya, S., Ewing, R. C. WALTER DE GRUYTER GMBH. 2006: 749–53
  • TEM characterization of Au nano-particles in TiO2 single crystals by ion implantation 14th International Conference on Ion Beam Modification of Materials (IBMM 2004) Zhu, S., Sun, K., Wang, L. M., Ewing, R. C., Fromknecht, R. ELSEVIER SCIENCE BV. 2006: 152–56
  • Ion-beam implantation and cross-sectional TEM characterization of Gd2Ti2O7 pyrochlore 14th International Conference on Ion Beam Modification of Materials (IBMM 2004) Lian, J., Wang, L. M., Ewing, R. C., Boatner, L. A. ELSEVIER SCIENCE BV. 2006: 448–51
  • Radiation-induced decomposition of U(VI) alteration phases of UO2 29th International Symposium on the Scientific Basis for Nuclear Waste Management Utsunomiya, S., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2006: 465–472
  • How does surface modification aid in the dispersion of carbon nanofibers? JOURNAL OF PHYSICAL CHEMISTRY B Zhao, J., Schaefer, D. W., SHI, D. L., Lian, J., Brown, J., BEAUCAGE, G., Wang, L. M., Ewing, R. C. 2005; 109 (49): 23351-23357

    Abstract

    Small-angle light scattering is used to assess the dispersion behavior of vapor-grown carbon nanofibers suspended in water. These data provide the first insights into the mechanism by which surface treatment promotes dispersion. Both acid-treated and untreated nanofibers exhibit hierarchical morphology consisting of small-scale aggregates (small bundles) that agglomerate to form fractal clusters that eventually precipitate. Although the morphology of the aggregates and agglomerates is nearly independent of surface treatment, their time evolution is quite different. The time evolution of the small-scale bundles is studied by extracting the size distribution from the angle-dependence of the scattered intensity, using the maximum entropy method in conjunction with a simplified tube form factor. The bundles consist of multiple tubes possibly aggregated side-by-side. Acid oxidation has little effect on this bundle morphology. Rather acid treatment inhibits agglomeration of the bundles. The time evolution of agglomeration is followed by fitting the scattering data to a generalized fractal model. Agglomerates appear immediately after cessation of sonication for untreated fibers but only after hours for treated fibers. Eventually, however, both systems precipitate.

    View details for DOI 10.1021/jp055129f

    View details for Web of Science ID 000233864300040

    View details for PubMedID 16375306

  • Ion beam implantation and cross-sectional TEM studies of lanthanide titanate pyrochlore single crystals 18th International Conference on Application of Accelerators in Research and Industry (CAARI) Lian, J., Wang, L. M., Ewing, R. C., Boatner, L. A. ELSEVIER SCIENCE BV. 2005: 365–71
  • Radiation-induced decomposition of U(VI) phases to nanocrystals of UO2 EARTH AND PLANETARY SCIENCE LETTERS Utsunomiya, S., Ewing, R. C., Wang, L. M. 2005; 240 (2): 521-528
  • Ion-induced damage accumulation and electron-beam-enhanced recrystallization in SrTiO3 PHYSICAL REVIEW B Zhang, Y., Lian, J., Wang, C. M., Jiang, W., Ewing, R. C., Weber, W. J. 2005; 72 (9)
  • Electron microscopy investigation of structural transformations in tungsten oxide (WO3) thin films PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE Ramana, C. V., Utsunomiya, S., Ewing, R. C., Julien, C. M., Becker, U. 2005; 202 (10): R108-R110
  • Cadmium nanowire formation induced by ion irradiation ADVANCED MATERIALS Jiang, W. L., Weber, W. J., Wang, C. M., Young, J. S., Boatner, L. A., Lian, J., Wang, L. M., Ewing, R. C. 2005; 17 (13): 1602-?
  • Solubility of gold in arsenian pyrite GEOCHIMICA ET COSMOCHIMICA ACTA Reich, M., Kesler, S. E., Utsunomiya, S., Palenik, C. S., Chryssoulis, S. L., Ewing, R. C. 2005; 69 (11): 2781-2796
  • Ion-beam-induced amorphization and order-disorder transition in the murataite structure JOURNAL OF APPLIED PHYSICS Lian, J., Wang, L. M., Ewing, R. C., Yudintsev, S. V., Stefanovsky, S. V. 2005; 97 (11)

    View details for DOI 10.1063/1.1926394

    View details for Web of Science ID 000229804700052

  • The corrosion of UO2 versus ThO2: A quantum mechanical investigation 15th Annual V M Goldschmidt Conference Skomurski, F. N., Shuller, L. C., Becker, U., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2005: A411–A411
  • The epsilon phase in the UO2 of the Oklo natural reactors 15th Annual V M Goldschmidt Conference Utsunomiya, S., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2005: A477–A477
  • Natural uranium getters in near surface environments at the Nopal I deposit, Pena Blanca, Mexico 15th Annual V M Goldschmidt Conference Fayek, M., Utsunomiya, S., Ewing, R. C., Simmons, A. PERGAMON-ELSEVIER SCIENCE LTD. 2005: A474–A474
  • Characterization of Nd, Te and U isotope ratios in UO2 using SIMS 15th Annual V M Goldschmidt Conference Fayek, M., Palenik, C. S., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2005: A378–A378
  • Uraninite recrystallization and Pb loss in the Oklo and Bangombe natural fission reactors, Gabon GEOCHIMICA ET COSMOCHIMICA ACTA Evins, L. Z., Jensen, K. A., Ewing, R. C. 2005; 69 (6): 1589-1606
  • Magnetic alignment of carbon nanofibers in polymer composites and anisotropy of mechanical properties JOURNAL OF APPLIED PHYSICS Shi, D. L., He, P., Lian, J., Chaud, X., Bud'ko, S. L., Beaugnon, E., Wang, L. M., Ewing, R. C., Tournier, R. 2005; 97 (6)

    View details for DOI 10.1063/1.1861143

    View details for Web of Science ID 000227767700079

  • Geochemical fixation of rare earth elements into secondary minerals in sandstones beneath a natural fission reactor at Bangombe, Gabon GEOCHIMICA ET COSMOCHIMICA ACTA Hidaka, H., Janeczek, J., Skomurski, F. N., Ewing, R. C., Gauthier-Lafaye, F. 2005; 69 (3): 685-694
  • Radiation effects in ferrate garnet JOURNAL OF NUCLEAR MATERIALS Utsunomiya, S., Yudintsev, S., Ewing, R. C. 2005; 336 (2-3): 251-260
  • Effects of electron irradiation in nuclear waste glasses Symposium on Microstructural Process in Irradiated Materials held at the Annual Meeting of the Minerals-Metals-and-Materials-Society Sun, K., Wang, L. M., Ewing, R. C., Weber, W. J. TAYLOR & FRANCIS LTD. 2005: 597–608
  • Plasma deposition of thin carbonfluorine films on aligned carbon nanotube APPLIED PHYSICS LETTERS He, P., Shi, D. L., Lian, J., Wang, L. M., Ewing, R. C., van Ooij, W., Li, W. Z., Ren, Z. F. 2005; 86 (4)

    View details for DOI 10.1063/1.1846957

    View details for Web of Science ID 000226761400065

  • Plutonium and "minor' actinides: safe sequestration EARTH AND PLANETARY SCIENCE LETTERS Ewing, R. C. 2005; 229 (3-4): 165-181
  • Electron irradiation induced transformation of (Pb5Ca5)(VO4)(6)F-2 apatite to CaVO3 perovskite JOURNAL OF THE AMERICAN CERAMIC SOCIETY Dong, Z. L., White, T. J., Sun, K., Wang, L. M., Ewing, R. C. 2005; 88 (1): 184-190
  • Microscale characterization of uranium(VI) silicate solids and associated neptunium(V) RADIOCHIMICA ACTA Douglas, M., Clark, S. B., Friese, J. I., Arey, B. W., Buck, E. C., Hanson, B. D., Utsunomiya, S., Ewing, R. C. 2005; 93 (5): 265-272
  • Thermally induced phase decomposition and nanocrystal formation in murataite ceramics JOURNAL OF MATERIALS CHEMISTRY Lian, J., Wang, L. M., Ewing, R. C., Yudintsev, S. V., Stefanovsky, S. V. 2005; 15 (6): 709-714

    View details for DOI 10.1039/b411845f

    View details for Web of Science ID 000226703500012

  • Radiation and thermal effects on porous and layer structured materials as getters of radionuclides CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE Wang, L. M., Chen, J., Ewing, R. C. 2004; 8 (6): 405-418
  • Comment on "Probabilistic risk analysis for a high-level radioactive waste repository" by B. L. Cohen in Risk analysis, volume 23, 909-915 RISK ANALYSIS Ewing, R. C., Palenik, C. S., Konikow, L. F. 2004; 24 (6): 1417-1419

    View details for Web of Science ID 000226235800001

    View details for PubMedID 15660599

  • Nanoscale occurrence of Pb in an Archean zircon GEOCHIMICA ET COSMOCHIMICA ACTA Utsunomiya, S., Palenik, C. S., Valley, J. W., Cavosie, A. J., Wilde, S. A., Ewing, R. C. 2004; 68 (22): 4679-4686
  • TEM observation of oxide scale formed on a Ti-Al-Zr alloy oxidized at 360 degrees C in alkaline steam PHILOSOPHICAL MAGAZINE LETTERS Liu, Y. Z., Zu, X. T., Lian, J., Wang, L., Huang, X. Q., Wang, Z. G., Wang, L. M., Ewing, R. C. 2004; 84 (11): 705-712
  • "Invisible" gold revealed: Direct imaging of gold nanoparticles in a Carlin-type deposit AMERICAN MINERALOGIST Palenik, C. S., Utsunomiya, S., Reich, M., Kesler, S. E., Wang, L. M., Ewing, R. C. 2004; 89 (10): 1359-1366
  • Probing cation antisite disorder in Gd2Ti2O7 pyrochlore by site-specific near-edge x-ray-absorption fine structure and x-ray photoelectron spectroscopy PHYSICAL REVIEW B Nachimuthu, P., Thevuthasan, S., Engelhard, M. H., Weber, W. J., Shuh, D. K., Hamdan, N. M., Mun, B. S., Adams, E. M., McCready, D. E., Shutthanandan, V., Lindle, D. W., Balakrishnan, G., PAUL, D. M., Gullikson, E. M., Perera, R. C., Lian, J., Wang, L. M., Ewing, R. C. 2004; 70 (10)
  • Applications of near-infrared FT-Raman spectroscopy in metamict and annealed zircon: oxidation state of U ions PHYSICS AND CHEMISTRY OF MINERALS Zhang, M., Salje, E. K., Ewing, R. C., Daniel, P., Geisler, T. 2004; 31 (7): 405-414
  • First-principles calculation of defect-formation energies in the Y-2(Ti,Sn,Zr)(2)O-7 pyrochlore PHYSICAL REVIEW B Panero, W. R., Stixrude, L., Ewing, R. C. 2004; 70 (5)
  • Microstructural evolution and nanocrystal formation in Pb+-implanted ZrSiO4 single crystals (vol 94, pg 5695, 2003) JOURNAL OF APPLIED PHYSICS Lian, J., Rios, S., Boatner, L. A., Wang, L. M., Ewing, R. C. 2004; 96 (1): 937-937

    View details for DOI 10.1063/1.1753069

    View details for Web of Science ID 000222093300151

  • Nuclear waste disposal-pyrochlore (A(2)B(2)O(7)): Nuclear waste form for the immobilization of plutonium and "minor" actinides JOURNAL OF APPLIED PHYSICS Ewing, R. C., Weber, W. J., Lian, J. 2004; 95 (11): 5949-5971

    View details for DOI 10.1063/1.1707213

    View details for Web of Science ID 000221657300001

  • Cr(VI) reduction by green rust 14th Annual V M Goldschmidt Conference Skovbjerg, L. L., Stipp, S. L., Utsunomiya, S., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2004: A138–A138
  • Quantum mechanical versus empirical potential modeling of UO2 surface-water interactions 14th Annual V M Goldschmidt Conference Skomurski, F. N., Becker, U., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2004: A119–A119
  • The environmental impact of the nuclear fuel cycle: Climate change, nuclear waste & nuclear weapons 14th Annual V M Goldschmidt Conference Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2004: A13–A13
  • Ion beam irradiation in La2Zr2O7-Ce2Zr2O7 pyrochlore 12th International Conference on Radiation Effects in Insulators Lian, J., Wang, L. M., Haire, R. G., Helean, K. B., Ewing, R. C. ELSEVIER SCIENCE BV. 2004: 236–243
  • Electron irradiation induced phase separation in a sodium borosilicate glass 12th International Conference on Radiation Effects in Insulators Sun, K., Wang, L. M., Ewing, R. C., Weber, W. J. ELSEVIER SCIENCE BV. 2004: 368–374
  • Formation enthalpies of rare earth titanate pyrochlores JOURNAL OF SOLID STATE CHEMISTRY Helean, K. B., Ushakov, S. V., Brown, C. E., Navrotsky, A., Lian, J., Ewing, R. C., Farmer, J. M., Boatner, L. A. 2004; 177 (6): 1858-1866
  • Ion-beam irradiation of Gd2Sn2O7 and Gd2Hf2O7 pyrochlore: Bond-type effect JOURNAL OF MATERIALS RESEARCH Lian, J., Ewing, R. C., Wang, L. M., Helean, K. B. 2004; 19 (5): 1575-1580
  • Direct identification of trace metals in fine and ultrafine particles in the Detroit urban atmosphere ENVIRONMENTAL SCIENCE & TECHNOLOGY Utsunomiya, S., Jensen, K. A., Keeler, G. J., Ewing, R. C. 2004; 38 (8): 2289-2297

    Abstract

    Exposure to airborne particulates containing low concentrations of heavy metals, such as Pb, As, and Se, may have serious health effects. However, little is known about the speciation and particle size of these airborne metals. Fine- and ultrafine particles with heavy metals in aerosol samples from the Detroit urban area, Michigan, were examined in detail to investigate metal concentrations and speciation. The characterization of individual particles was completed using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) combined with conventional high-resolution TEM techniques. The trace elements, Pb, As, La, Ce, Sr, Zn, Cr, Se, Sn, Y, Zr, Au, and Ag, were detected, and the elemental distributions were mapped in situ atthe nanoscale. The crystal structures of the particles containing Pb, Sr, Zn, and Au were determined from their electron diffraction patterns. Based on the characterization of the representative trace element particles, the potential health effects are discussed. Most of the trace element particles detected in this study were within a range of 0.01-1.0 microm in size, which has the longest atmospheric residence time (approximately 100 days). Increased chemical reactivity owing to the size of nanoparticles may be expected for most of the trace metal particles observed.

    View details for DOI 10.1021/es035010p

    View details for Web of Science ID 000220857400005

    View details for PubMedID 15116832

  • Radiation-induced nanostructures in an iron phosphate glass Symposium on Radiation Effects and Ion-Beam Processing of Materials held at the 2003 MRS Fall Meeting Sun, K., Ding, T., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2004: 177–182
  • Nficrostructure and chemistry of an aluminophosphate glass waste form under electron beam irradiation 27th Symposium on Scientific Basis for Nuclear Waste Management Sun, K., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2004: 121–126
  • Ion beam-induced amorphization of the pyrochlore structure-type: A review Symposium on Radiation Effects and Ion-Beam Processing of Materials held at the 2003 MRS Fall Meeting Ewing, R. C., Lian, J., Wang, L. M. MATERIALS RESEARCH SOCIETY. 2004: 37–48
  • Radiation effects in murataite ceramics 27th Symposium on Scientific Basis for Nuclear Waste Management Lian, J., Wang, L. M., Ewing, R. C., Yudintsev, S. V., Stefanovsky, S. V. MATERIALS RESEARCH SOCIETY. 2004: 225–230
  • MAS NMR study on the microstructural changes of zeolite-NaY under neutron irradiation Symposium on Radiation Effects and Ion-Beam Processing of Materials held at the 2003 MRS Fall Meeting Chen, J., Beck, L. W., Wang, L. M., Gu, B. X., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2004: 417–422
  • Performance assessments of geologic repositories for high-level nuclear waste: Are they necessary or sufficient? 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2004: 511–520
  • Yucca Mountain: Earth-science issues at a geologic repository for high-level nuclear waste ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES Long, J. C., Ewing, R. C. 2004; 32: 363-401
  • Colloid transport of radionuclides: Yucca mountain performance assessment 27th Symposium on Scientific Basis for Nuclear Waste Management Traexler, K. A., Utsunomiya, S., Kersting, A. B., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2004: 653–658
  • Uncertainties in geochemical models of natural systems: Implications for performance assessments 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting Palenik, C. S., Jensen, K. A., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2004: 543–548
  • Effect of radiation on properties of confinement matrices for immobilization of actinide-bearing wastes GEOLOGY OF ORE DEPOSITS Laverov, N. P., Yudintsev, S. V., Yudintseva, T. S., Stefanovsky, S. V., Ewing, R. C., Lian, J., Utsunomiya, S., Wang, L. A. 2003; 45 (6): 423-451
  • Ion-beam and electron-beam irradiation of synthetic britholite JOURNAL OF NUCLEAR MATERIALS Utsunomiya, S., Yudintsev, S., Wang, L. M., Ewing, R. C. 2003; 322 (2-3): 180-188
  • Microstructural evolution and nanocrystal formation in Pb+-implanted ZrSiO4 single crystals JOURNAL OF APPLIED PHYSICS Lian, J., Rios, S., Boatner, L. A., Wang, L. M., Ewing, R. C. 2003; 94 (9): 5695-5703

    View details for DOI 10.1063/1.1618917

    View details for Web of Science ID 000186138600036

  • Structural and magnetic characterization of CoxNi1-x nanoparticles in yttria-stabilized zirconia single crystals JOURNAL OF APPLIED PHYSICS Zhu, S., Sun, K., Zhang, Q. Y., Zu, X. T., Wang, L. M., Ewing, R. C. 2003; 94 (9): 5648-5651

    View details for DOI 10.1063/1.1615299

    View details for Web of Science ID 000186138600028

  • Nanoscale mineralogy of arsenic in a region of New Hampshire with elevated As-concentrations in the groundwater AMERICAN MINERALOGIST Utsunomiya, S., Peters, S. C., Blum, J. D., Ewing, R. C. 2003; 88 (11-12): 1844-1852
  • Radiation-induced amorphization of rare-earth titanate pyrochlores PHYSICAL REVIEW B Lian, J., Chen, J., Wang, L. M., Ewing, R. C., Farmer, J. M., Boatner, L. A., Helean, K. B. 2003; 68 (13)
  • Oxygen isotopic composition of nano-scale uraninite at the Oklo-Okelobondo natural fission reactors, Gabon AMERICAN MINERALOGIST Fayek, M., Utsunomiya, S., Ewing, R. C., Riciputi, L. R., Jensen, K. A. 2003; 88 (10): 1583-1590
  • REE mobility in groundwater proximate to the natural fission reactor at Bangombe (Gabon) CHEMICAL GEOLOGY Stille, P., Gauthier-Lafaye, F., Jensen, K. A., Salah, S., Bracke, G., Ewing, R. C., Louvat, D., Million, D. 2003; 198 (3-4): 289-304
  • Enthalpies of formation of U-, Th-, Ce-brannerite: implications for plutonium immobilization JOURNAL OF NUCLEAR MATERIALS Helean, K. B., NAVROTSKY, A., Lumpkin, G. R., Colella, M., Lian, J., Ewing, R. C., Ebbinghaus, B., Catalano, J. G. 2003; 320 (3): 231-244
  • Oxidation state of uranium in metamict and annealed zircon: near-infrared spectroscopic quantitative analysis JOURNAL OF PHYSICS-CONDENSED MATTER Zhang, M., Salje, E. K., Ewing, R. C. 2003; 15 (20): 3445-3470
  • Electron microscopy and optical spectroscopy study of xenon-implanted yttria-stabilized zirconia 13th International Conference on Ion Beam Modification of Materials Zhu, S., Zu, X. T., Xiang, X., Wang, Z. G., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2003: 1092–1096
  • Size effects in the irradiation-induced crystalline-to-amorphous transformation 104th Annual Meeting of the American-Ceramic-Society Meldrum, A., Boatner, L. A., Ewing, R. C. ELSEVIER SCIENCE BV. 2003: 28–35
  • Radiation damage in zircon AMERICAN MINERALOGIST Palenik, C. S., Nasdala, L., Ewing, R. C. 2003; 88 (5-6): 770-781
  • The order-disorder transition in ion-irradiated pyrochlore ACTA MATERIALIA Lian, J., Wang, L., Chen, J., Sun, K., Ewing, R. C., Farmer, J. M., Boatner, L. A. 2003; 51 (5): 1493-1502
  • Application of high-angle annular dark field scanning transmission electron microscopy, scanning transmission electron microscopy-energy dispersive X-ray spectrometry, and energy-filtered transmission electron microscopy to the characterization of nanoparticles in the environment ENVIRONMENTAL SCIENCE & TECHNOLOGY Utsunomiya, S., Ewing, R. C. 2003; 37 (4): 786-791

    Abstract

    A major challenge to the development of a fundamental understanding of transport and retardation mechanisms of trace metal contaminants (<10 ppm) is their identification and characterization at the nanoscale. Atomic-scale techniques, such as conventional transmission electron microscopy, although powerful, are limited by the extremely small amounts of material that are examined. However, recent advances in electron microscopy provide a number of new analytical techniques that expand its application in environmental studies, particularly those concerning heavy metals on airborne particulates or water-borne colloids. High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM-energy-dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM) can be effectively used to identify and characterize nanoparticles. The image contrast in HAADF-STEM is strongly correlated to the atomic mass: heavier elements contribute to brighter contrast. Gold nanocrystals in pyrite and uranium nanocrystals in atmospheric aerosols have been identified by HAADF-STEM and STEM-EDX mapping and subsequently characterized by high-resolution TEM (HRTEM). EFTEM was used to identify U and Fe nanocrystals embedded in an aluminosilicate. A rare, As-bearing nanophase, westerveldite (FeAs), was identified by STEM-EDX and HRTEM. The combined use of these techniques greatly expands the effective application of electron microscopy in environmental studies, especially when applied to metals of very low concentrations. This paper describes examples of how these electron microbeam techniques can be used in combination to characterize a low concentration of heavy metals (a few ppm) on nanoscale particles.

    View details for DOI 10.1021/es026053t

    View details for Web of Science ID 000181067100019

    View details for PubMedID 12636280

  • The effect of ionizing radiation on uranophane AMERICAN MINERALOGIST Utsunomiya, S., Wang, L. M., Douglas, M., Clark, S. B., Ewing, R. C. 2003; 88 (1): 159-166
  • Enthalpies of formation of cerium zirconate: (Ce,Zr)O-2 fiuorite and Ce2Zr2O7 Pyrochlore 3rd Topical Conference on Plutonium and Actinides Helean, K. B., Ushakov, S. V., Brown, C. E., NAVROTSKY, A., Lian, J., Ewing, R. C., Lee, T., Haire, R. AMER INST PHYSICS. 2003: 286–287
  • Analytical electron microscopy study of electron radiation damage in iron phosphate glass waste forms 26th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2002 MRS Fall Meeting Sun, K., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2003: 135–140
  • Structure-configurational entropy and its effect on the thermodynamic stability of uranyl phases: With special application for geological disposal of nuclear waste SCIENCE IN CHINA SERIES D-EARTH SCIENCES Chen, F. R., Ewing, R. C. 2003; 46 (1): 39-49
  • Uraninite and fullerene in atmospheric particulates ENVIRONMENTAL SCIENCE & TECHNOLOGY Utsunomiya, S., Jensen, K. A., Keeler, G. J., Ewing, R. C. 2002; 36 (23): 4943-4947

    Abstract

    Particulates emitted from coal-burning power plants typically contain very small amounts of uranium (<10 ppm). Because of the extremely low concentrations, the form of the uranium has been unknown. Using a variety of advanced electron microscopy techniques, we have identified for the first time nanocrystals of uraninite, UO2+x, encapsulated in carbonaceous matter (< or = 50 nm) similar to fullerene. We have also identified, for the first time, closely associated fullerenes, C60. The "carbon-caged" nanocrystals of uraninite are protected from the immediate oxidation that would lead to increased mobility of uranium in the environment. Still, the presence of uranium in the very fine fraction of atmospheric particulates provides another pathway for radiation exposure.

    View details for Web of Science ID 000179685000005

    View details for PubMedID 12523404

  • X-ray study of actinide host-phases formation Yudintsev, S. V., Stefanovsky, S. V., Jang, Y. N., Ewing, R. C. PERGAMON-ELSEVIER SCIENCE LTD. 2002: A866–A866
  • Ion-irradiation-induced amorphization of La2Zr2O7 pyrochlore PHYSICAL REVIEW B Lian, J., Zu, X. T., Kutty, K. V., Chen, J., Wang, L. M., Ewing, R. C. 2002; 66 (5)
  • REE migration in groundwaters close to the natural fission reactor of Bangombe (Gabon) Stille, P., Gauthier-Lafaye, F., Jensen, K. A., Bracke, G., Ewing, R., Louvat, D. PERGAMON-ELSEVIER SCIENCE LTD. 2002: A742–A742
  • Phase transformations during synthesis of actinide matrices DOKLADY EARTH SCIENCES Laverov, N. P., Yudintsev, S. V., Stefanovsky, S. V., Jang, Y., Lapina, M. I., Sivtsov, A. V., Ewing, R. 2002; 385 (6): 671-675
  • Yucca Mountain: Should we delay? Response SCIENCE Ewing, R. C., Macfarlane, A. 2002; 296 (5577): 2334-2335
  • Nanodomains of pyrochlore formed by Ti ion implantation in yttria-stabilized zirconia APPLIED PHYSICS LETTERS Zhu, S., Zu, X. T., Wang, L. M., Ewing, R. C. 2002; 80 (23): 4327-4329

    View details for DOI 10.1063/1.1482784

    View details for Web of Science ID 000175904600013

  • Ion irradiation-induced amorphization and nano-crystal formation in garnets JOURNAL OF NUCLEAR MATERIALS Utsunomiya, S., Wang, L. M., Yudintsev, S., Ewing, R. C. 2002; 303 (2-3): 177-187
  • X-ray photoelectron spectroscopy study of irradiation-induced amorphization of Gd2Ti2O7 (vol 79, pg 1989, 2001) APPLIED PHYSICS LETTERS Chen, J., Lian, J., Wang, L. M., Ewing, R. C., Boatner, L. A. 2002; 80 (19): 3650-3650

    View details for DOI 10.1063/1.1472474

    View details for Web of Science ID 000175464100062

  • Heavy ion irradiation effects of brannerite-type ceramics 11th International Conference on Radiation Effects in Insulators Lian, J., Wang, L. M., Lumpkin, G. R., Ewing, R. C. ELSEVIER SCIENCE BV. 2002: 565–570
  • Ion irradiation effects in natural garnets: Comparison with zircon 11th International Conference on Radiation Effects in Insulators Utsunomiya, S., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2002: 600–605
  • O and Pb isotopic analyses of uranium minerals by ion microprobe and U-Pb ages from the Cigar Lake deposit CHEMICAL GEOLOGY Fayek, M., Harrison, T. M., Ewing, R. C., Grove, M., Coath, C. D. 2002; 185 (3-4): 205-225
  • Nuclear waste - Yucca Mountain SCIENCE Ewing, R. C., MACFARLANE, A. 2002; 296 (5568): 659-660

    View details for Web of Science ID 000175281700027

    View details for PubMedID 11976429

  • Infrared spectra of Si-O overtones, hydrous species, and U ions in metamict zircon: radiation damage and recrystallization JOURNAL OF PHYSICS-CONDENSED MATTER Zhang, M., Salje, E. K., Ewing, R. C. 2002; 14 (12): 3333-3352
  • X-ray photoelectron spectroscopy study of disordering in Gd-2(Ti1-xZrx)(2)O-7 pyrochlores PHYSICAL REVIEW LETTERS Chen, J., Lian, J., Wang, L. M., Ewing, R. C., Wang, R. G., Pan, W. 2002; 88 (10)

    Abstract

    The dramatic increases in ionic conductivity in Gd2(Ti1-xZrx)2O7 solid solution are related to disordering on the cation and anion lattices. Disordering in Gd2(Ti1-xZrx)2O7 was characterized using x-ray photoelectron spectroscopy (XPS). As Zr substitutes for Ti in Gd2Ti2O7 to form Gd2(Ti1-xZrx)2O7 (0.25 < x < or =0.75), the corresponding O 1s XPS spectrum merges into a single symmetric peak. This confirms that the cation antisite disorder occurs simultaneously with anion disorder. Furthermore, the O 1s XPS spectrum of Gd2Zr2O7 experimentally suggests the formation of a split vacancy.

    View details for DOI 10.1103/PhysRevLett.88.105901

    View details for Web of Science ID 000174342000045

    View details for PubMedID 11909374

  • Amorphization and recrystallization of the ABO(3) oxides JOURNAL OF NUCLEAR MATERIALS Meldrum, A., Boatner, L. A., Weber, W. J., Ewing, R. C. 2002; 300 (2-3): 242-254
  • Structural alterations in titanate pyrochlores induced by ion irradiation: X ray photoelectron spectrum interpretation 25th Symposium on Scientific Basis for Nuclear Waste Management Chen, J., Lian, J., Wang, L. M., Ewing, R. C., Farmer, J. M., Boatner, L. A. MATERIALS RESEARCH SOCIETY. 2002: 501–506
  • Accommodation of uranium into the garnet structure 25th Symposium on Scientific Basis for Nuclear Waste Management Yudintsev, S. V., Lapina, M. I., Ptashkin, A. G., Ioudintseva, T. S., Utsunomiya, S., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2002: 477–480
  • Radiation effects in crystalline oxide host phases for the immobilization of actinides 25th Symposium on Scientific Basis for Nuclear Waste Management Weber, W. J., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2002: 443–454
  • In situ isotopic analysis of uraninite microstructures from the Oklo-Okelobondo natural fission reactors, Gabon 25th Symposium on Scientific Basis for Nuclear Waste Management Fayek, M., Jensen, K. A., Ewing, R. C., Riciputi, L. R. MATERIALS RESEARCH SOCIETY. 2002: 849–856
  • Ion irradiation effects in synthetic garnets incorporating actinides 25th Symposium on Scientific Basis for Nuclear Waste Management Utsunomiya, S., Wan, L. M., Yadintsev, S., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2002: 495–500
  • Heavy ion irradiation of zirconate pyrochlores 25th Symposium on Scientific Basis for Nuclear Waste Management Lian, J., Wang, L. M., Chen, J., Ewing, R. C., Kutty, K. V. MATERIALS RESEARCH SOCIETY. 2002: 507–512
  • Ion-induced amorphization of murataite 25th Symposium on Scientific Basis for Nuclear Waste Management Lian, J., Yudintsev, S. V., Stefanovsky, S. V., Kirjanova, O. I., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2002: 455–460
  • The effects of radiation on the retention of strontium in zeolite-NaSrY JOURNAL OF MATERIALS CHEMISTRY Gu, B. X., Wang, L. M., Ewing, R. C. 2002; 12 (2): 233-238
  • Cesium ton implantation in single crystal yttria-stabilized zirconia (YSZ) and polycrystalline MgAl2O4-YSZ 25th Symposium on Scientific Basis for Nuclear Waste Management Zhu, S., Zu, X. T., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2002: 327–332
  • U6+ phases in the weathering zone of the Bangombe U-deposit: observed and predicted mineralogy RADIOCHIMICA ACTA Jensen, K. A., Palenik, C. S., Ewing, R. C. 2002; 90 (9-11): 761-769
  • An empirical method for calculating thermodynamic parameters for U(VI) phases, applications to performance assessment calculations Workshop on Use of Thermodynamic Databases in Performance Assessment Ewing, R. C., Chen, F. R., Clark, S. B. ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT. 2002: 93–102
  • Microanalysis of radiation damage across a zoned zircon crystal 25th Symposium on Scientific Basis for Nuclear Waste Management Palenik, C. S., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2002: 521–526
  • Nanoscale manipulation of pyrochlore: New nanocomposite ionic conductors PHYSICAL REVIEW LETTERS Lian, J., Wang, L. M., Wang, S. X., Chen, J., Boatner, L. A., Ewing, R. C. 2001; 87 (14)

    Abstract

    The ionic conductivity of isometric pyrochlore, ideally A2B2O (7), is extremely sensitive to disordering of A- and B-site cations and oxygen anion vacancies. We report the first use of ion beam irradiation-induced disordering in Gd 2Ti 2O (7) to produce a strain-free, buried, disordered defect-fluorite layer approximately 12 nm thick within an ordered pyrochlore matrix. This approach provides a new means of creating nanoscale, mixed ionic-electronic conductors in pyrochlore ceramics, such as those required for solid-state electrochemical cells.

    View details for DOI 10.1103/PhysRevLett.87.145901

    View details for Web of Science ID 000171427500031

    View details for PubMedID 11580662

  • X-ray photoelectron spectroscopy study of irradiation-induced amorphizaton of Gd2Ti2O7 APPLIED PHYSICS LETTERS Chen, J., Lian, J., Wang, L. M., Ewing, R. C., Boatner, L. A. 2001; 79 (13): 1989-1991
  • Temperature effects on the radiation stability and ion exchange capacity of smectites JOURNAL OF NUCLEAR MATERIALS Gu, B. X., Wang, L. M., Minc, L. D., Ewing, R. C. 2001; 297 (3): 345-354
  • Radiation damage and nanocrystal formation in uranium-niobium titanates JOURNAL OF NUCLEAR MATERIALS Lian, J., Wang, S. X., Wang, L. M., Ewing, R. C. 2001; 297 (1): 89-96
  • The design and evaluation of nuclear-waste forms: Clues from mineralogy CANADIAN MINERALOGIST Ewing, R. C. 2001; 39: 697-715
  • Radiation resistance of fused titanium ceramic for actinide immobilization ATOMIC ENERGY Yudintsev, S. V., Stefanovskii, S. V., Kir'yanova, O. I., Lian, J., Ewing, R. 2001; 90 (6): 487-494
  • Ion irradiation-induced amorphization of two GeO2 polymorphs 12th International Conference on Ion Beam Modification of Materials (IBMM2000) Wang, S. X., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2001: 615–619
  • Irradiation-induced amorphization of Cd2Nb2O7 pyrochlore PHYSICAL REVIEW B Meldrum, A., White, C. W., Keppens, V., Boatner, L. A., Ewing, R. C. 2001; 63 (10)
  • Nuclear waste form glasses: The evaluation of very long-term behaviour MATERIALS TECHNOLOGY Ewing, R. C. 2001; 16 (1): 30-36
  • Effects of fission product incorporation on the microstructure of cubic zirconia 6th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments held at the 102nd Annual Meeting of the Amer-Ceram-Soc Wang, L. M., Wang, S. X., Zhu, S., Ewing, R. C. ELSEVIER SCIENCE BV. 2001: 122–27
  • Radiation stability of actinide matrices DOKLADY EARTH SCIENCES Laverov, N. P., Yudintsev, S. V., Stefanovsky, S. V., Lian, J., Ewing, R. 2001; 377 (2): 175-177
  • Irradiation-induced amorphization: Effects of temperature, ion mass, cascade size, and dose rate PHYSICAL REVIEW B Wang, S. X., Wang, L. M., Ewing, R. C. 2001; 63 (2)
  • Effects of xenon implantation in spinel-zirconia/ceria composites 6th Workshop on Inert Matrix Fuel, E-MRS Symposium B Wang, L. M., Zhu, S., Wang, S. X., Ewing, R. C., Boucharat, N., Fernandez, A., Matzke, H. PERGAMON-ELSEVIER SCIENCE LTD. 2001: 295–300
  • The Okelobondo natural fission reactor, southeast Gabon: Geology, mineralogy, and retardation of nuclear-reaction products GEOLOGICAL SOCIETY OF AMERICA BULLETIN Jensen, K. A., Ewing, R. C. 2001; 113 (1): 32-62
  • Synthesis and characterization of a new microporous cesium silicotitanate (SNL-B) molecular sieve MICROPOROUS AND MESOPOROUS MATERIALS Nyman, M., Gu, B. X., Wang, L. M., Ewing, R. C., Nenoff, T. M. 2000; 40 (1-3): 115-125
  • Integrated experimental and computational methods for structure determination and characterization of a new, highly stable cesium silicotitanate phase, Cs2TiSi6O15 (SNL-A) CHEMISTRY OF MATERIALS Nyman, M., Bonhomme, F., Teter, D. M., Maxwell, R. S., Gu, B. X., Wang, L. M., Ewing, R. C., Nenoff, T. M. 2000; 12 (11): 3449-3458

    View details for DOI 10.1021/cm000259g

    View details for Web of Science ID 000165462800034

  • Memorial of Arthur Montgomery, 1909-1999 AMERICAN MINERALOGIST Ewing, R. C. 2000; 85 (11-12): 1848-1850
  • Plutonium immobilization and radiation effects SCIENCE Weber, W. J., Ewing, R. C. 2000; 289 (5487): 2051-2052

    View details for Web of Science ID 000089430900019

    View details for PubMedID 17799393

  • Nano-scale glass formation in pyrochlore by heavy ion irradiation 9th International Conference on the Physics of Non-Crystalline Solids (PNS 1999) Wang, S. X., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2000: 238–43
  • Irradiation-induced nanostructures International-Union-of-Materials-Research-Societies International Conference on Advanced Materials (IUMRS-ICAM 99) Wang, L. M., Wang, S. X., Ewing, R. C., Meldrum, A., BIRTCHER, R. C., Provencio, P. N., Weber, W. J., Matzke, H. ELSEVIER SCIENCE SA. 2000: 72–80
  • Alpha-decay damage and recrystallization in zircon: evidence for an intermediate state from infrared spectroscopy JOURNAL OF PHYSICS-CONDENSED MATTER Zhang, M., Salje, E. K., Ewing, R. C., Farnan, I., Rios, S., Schluter, J., Leggo, P. 2000; 12 (24): 5189-5199
  • Ion irradiation of rare-earth- and yttrium-titanate-pyrochlores International-Union-of-Materials-Research-Societies International Conference on Advanced Materials (IUMRS-ICAM 99) Wang, S. X., Wang, L. M., Ewing, R. C., Kutty, K. V. ELSEVIER SCIENCE BV. 2000: 135–140
  • Amorphization of cubic zirconia by caesium-ion implantation PHILOSOPHICAL MAGAZINE LETTERS Wang, L. M., Wang, S. X., Ewing, R. C. 2000; 80 (5): 341-347
  • Ion irradiation-induced amorphization of six zirconolite compositions 10th International Conference on Radioation Effects in Insulators (REI-10) Wang, S. X., Lumpkin, G. R., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 2000: 293–298
  • Annealing of alpha-decay damage in zircon: a Raman spectroscopic study JOURNAL OF PHYSICS-CONDENSED MATTER Zhang, M., Salje, E. K., Capitani, G. C., Leroux, H., Clark, A. M., Schluter, J., Ewing, R. C. 2000; 12 (13): 3131-3148
  • A comparison of radiation effects in crystalline ABO(4)-type phosphates and silicates MINERALOGICAL MAGAZINE Meldrum, A., Boatner, L. A., Ewing, R. C. 2000; 64 (2): 185-194
  • Electron and ion irradiation of zeolites JOURNAL OF NUCLEAR MATERIALS Wang, S. X., Wang, L. M., Ewing, R. C. 2000; 278 (2-3): 233-241
  • Near-field behavior of Tc-99 during the oxidative alteration of spent nuclear fuel JOURNAL OF NUCLEAR MATERIALS Chen, F. R., Burns, P. C., Ewing, R. C. 2000; 278 (2-3): 225-232
  • XAS and XRD study of annealed Pu-238- and Pu-239-substituted zircons (Zr0.92Pu0.08SiO4) JOURNAL OF NUCLEAR MATERIALS Begg, B. D., Hess, N. J., Weber, W. J., Conradson, S. D., Schweiger, M. J., Ewing, R. C. 2000; 278 (2-3): 212-224
  • Amorphization in zircon: evidence for direct impact damage JOURNAL OF PHYSICS-CONDENSED MATTER Rios, S., Salje, E. K., Zhang, M., Ewing, R. C. 2000; 12 (11): 2401-2412
  • Ion irradiation effects in nonmetals: formation of nanocrystals and novel microstructures MATERIALS RESEARCH INNOVATIONS Meldrum, A., Boatner, L. A., White, C. W., Ewing, R. C. 2000; 3 (4): 190-204
  • The effect of amorphization on the Cs ion exchange and retention capacity of zeolite-NaY JOURNAL OF NUCLEAR MATERIALS Gu, B. X., Wang, L. M., Ewing, R. C. 2000; 278 (1): 64-72
  • Reaction sintered glass: a durable matrix for spinel-forming nuclear waste compositions JOURNAL OF NUCLEAR MATERIALS Gong, W. L., Lutze, W., Ewing, R. C. 2000; 278 (1): 73-84
  • Metamictization of zircon: Raman spectroscopic study JOURNAL OF PHYSICS-CONDENSED MATTER Zhang, M., Salje, E. K., Farnan, I., Graeme-Barber, A., Daniel, P., Ewing, R. C., Clark, A. M., Leroux, H. 2000; 12 (8): 1915-1925
  • Zirconia ceramics for excess weapons plutonium waste JOURNAL OF NUCLEAR MATERIALS Gong, W. L., Lutze, W., Ewing, R. C. 2000; 277 (2-3): 239-249
  • Micro-structures associated with uraninite alteration JOURNAL OF NUCLEAR MATERIALS Fayek, M., Burns, P., Guo, Y. X., Ewing, R. C. 2000; 277 (2-3): 204-210
  • The effect of H+ irradiation on the Cs-ion exchange capacity of zeolite-NaY JOURNAL OF MATERIALS CHEMISTRY Gu, B. X., Wang, L. M., Wang, S. X., Zhao, D. G., Rotberg, V. H., Ewing, R. C. 2000; 10 (11): 2610-2616
  • An overview of the crystal chemistry, durability, and radiation damage effects of natural pyrochlore 24th International Symposium on Scientific Basis for Nuclear Waste Management Lumpkin, G. R., Ewing, R. C., Williams, C. T., Mariano, A. N. MATERIALS RESEARCH SOCIETY. 2000: 921–934
  • Plutonium stabilization in zircon: Effects of self-radiation Topical Conference on Plutonium and Actinides Weber, W. J., Hess, N. J., Williford, R. E., Heinisch, H. L., Begg, B. D., Conradson, S. D., Ewing, R. C. AMER INST PHYSICS. 2000: 18–19
  • Effects of cesium, iodine and strontium ion implantation on the microstructure of cubic zirconia 24th International Symposium on Scientific Basis for Nuclear Waste Management Wang, L. M., Zhu, S., Wang, S. X., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2000: 293–300
  • Gadolinium borosilicate glass-bonded Gd-silicate apatite: A glass-ceramic nuclear waste form for actinides 24th International Symposium on Scientific Basis for Nuclear Waste Management Zhao, D. G., Li, L. Y., Davis, L. L., Weber, W. J., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2000: 199–206
  • Radiation effects on materials in the near-field of a nuclear waste repository 24th International Symposium on Scientific Basis for Nuclear Waste Management Gu, B. X., Wang, L. M., Wang, S. X., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 2000: 883–891
  • Radiation effects in uranium-niobium titanates Topical Conference on Plutonium and Actinides Lian, J., Wang, S. X., Wang, L. M., Ewing, R. C. AMER INST PHYSICS. 2000: 403–405
  • Effects of fission product accumulation in cubic zirconia Topical Conference on Plutonium and Actinides Wang, L. M., Wang, S. X., Zhu, S., Ewing, R. C. AMER INST PHYSICS. 2000: 95–97
  • Alteration products of uraninite from the Colorado Plateau 7th International Conference on Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere (MIGRATION 99) Zhao, D., Ewing, R. C. OLDENBOURG VERLAG. 2000: 739–49
  • Radiation effects in nuclear waste materials and their consequences 6th International Congress on Applied Mineralogy (ICAM 2000) Wang, M. L., Ewing, R. C. A A BALKEMA PUBLISHERS. 2000: 87–87
  • Radiation resistance of gadolinium zirconate pyrochlore Topical Conference on Plutonium and Actinides Wang, S. X., Wang, L. M., Ewing, R. C., Kutty, K. V., Weber, W. J. AMER INST PHYSICS. 2000: 15–17
  • Radiation-induced amorphization TRANSFORMATION PROCESSES IN MINERALS Ewing, R. C., Meldrum, A., Wang, L. M., Wang, S. X. 2000; 39: 319-361
  • Radiation stability of gadolinium zirconate: A waste form for plutonium disposition JOURNAL OF MATERIALS RESEARCH Wang, S. X., Begg, B. D., Wang, L. M., Ewing, R. C., Weber, W. J., Kutty, K. V. 1999; 14 (12): 4470-4473
  • Comparison of ion-beam irradiation effects in X2YO4 compounds 100th Annual Meeting of the American-Ceramic-Society Wang, L. M., Gong, W. L., Wang, S. X., Ewing, R. C. WILEY-BLACKWELL PUBLISHING, INC. 1999: 3321–29
  • Radioactive waste - Less geology in the geological disposal of nuclear waste SCIENCE Ewing, R. C. 1999; 286 (5439): 415-?
  • Se-79: geochemical and crystallo-chemical retardation mechanisms JOURNAL OF NUCLEAR MATERIALS Chen, F. R., Burns, P. C., Ewing, R. C. 1999; 275 (1): 81-94
  • Performance assessments of nuclear waste repositories: A dialogue on their value and limitations RISK ANALYSIS Ewing, R. C., Tierney, M. S., Konikow, L. F., Rechard, R. P. 1999; 19 (5): 933-958

    Abstract

    Performance Assessment (PA) is the use of mathematical models to simulate the long-term behavior of engineered and geologic barriers in a nuclear waste repository; methods of uncertainty analysis are used to assess effects of parametric and conceptual uncertainties associated with the model system upon the uncertainty in outcomes of the simulation. PA is required by the U.S. Environmental Protection Agency as part of its certification process for geologic repositories for nuclear waste. This paper is a dialogue to explore the value and limitations of PA. Two "skeptics" acknowledge the utility of PA in organizing the scientific investigations that are necessary for confident siting and licensing of a repository; however, they maintain that the PA process, at least as it is currently implemented, is an essentially unscientific process with shortcomings that may provide results of limited use in evaluating actual effects on public health and safety. Conceptual uncertainties in a PA analysis can be so great that results can be confidently applied only over short time ranges, the antithesis of the purpose behind long-term, geologic disposal. Two "proponents" of PA agree that performance assessment is unscientific, but only in the sense that PA is an engineering analysis that uses existing scientific knowledge to support public policy decisions, rather than an investigation intended to increase fundamental knowledge of nature; PA has different goals and constraints than a typical scientific study. The "proponents" describe an ideal, six-step process for conducting generalized PA, here called probabilistic systems analysis (PSA); they note that virtually all scientific content of a PA is introduced during the model-building steps of a PSA; they contend that a PA based on simple but scientifically acceptable mathematical models can provide useful and objective input to regulatory decision makers. The value of the results of any PA must lie between these two views and will depend on the level of knowledge of the site, the degree to which models capture actual physical and chemical processes, the time over which extrapolations are made, and the proper evaluation of health risks attending implementation of the repository. The challenge is in evaluating whether the quality of the PA matches the needs of decision makers charged with protecting the health and safety of the public.

    View details for Web of Science ID 000083825000008

    View details for PubMedID 10765440

  • Refinement of the crystal structure of rutherfordine CANADIAN MINERALOGIST Finch, R. J., Cooper, M. A., Hawthorne, F. C., Ewing, R. C. 1999; 37: 929-938
  • Is "metamictization" of zircon a phase transition? AMERICAN MINERALOGIST Salje, E. K., Chrosch, J., Ewing, R. C. 1999; 84 (7-8): 1107-1116
  • Is a probabilistic performance assessment enough? GROUND WATER Konikow, L. E., Ewing, R. C. 1999; 37 (4): 481-482
  • The Gibbs free energies and enthalpies of formation of U6+ phases: An empirical method of prediction AMERICAN MINERALOGIST Chen, F. R., Ewing, R. C., Clark, S. B. 1999; 84 (4): 650-664
  • Effects of dose rate and temperature on the crystalline-to-metamict transformation in the ABO(4) orthosilicates CANADIAN MINERALOGIST Meldrum, A., Boatner, L. A., Zinkle, S. J., Wang, S. X., Wang, L. M., Ewing, R. C. 1999; 37: 207-221
  • Vitrification of radioactive waste by reaction sintering under pressure JOURNAL OF NUCLEAR MATERIALS Gong, W. L., Lutze, W., Abdelouas, A., Ewing, R. C. 1999; 265 (1-2): 12-21
  • Formation of oriented particles in an amorphous host: ZnS nanocrystals in silicon APPLIED PHYSICS LETTERS Meldrum, A., ZUHR, R. A., Sonder, E., Budai, J. D., White, C. W., Boatner, L. A., Ewing, R. C., Henderson, D. O. 1999; 74 (5): 697-699
  • Heavy-ion irradiation effects in the ABO(4) orthosilicates: Decomposition, amorphization, and recrystallization PHYSICAL REVIEW B Meldrum, A., Zinkle, S. J., Boatner, L. A., Ewing, R. C. 1999; 59 (6): 3981-3992
  • Surface features and alteration products of natural zirconolite leached in silica-saturated solutions 22nd Symposium on Scientific Basis for Nuclear Waste Management held at the 1998 MRS Fall Meeting Helean, K. B., Lutze, W., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 157–164
  • Se-79: Geochemical and crystallo-chemical retardation mechanisms 22nd Symposium on Scientific Basis for Nuclear Waste Management held at the 1998 MRS Fall Meeting Chen, F. R., Burns, P. C., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 1115–1122
  • Pyrochlore-type phases for actinides and rare earth elements immobilization 22nd Symposium on Scientific Basis for Nuclear Waste Management held at the 1998 MRS Fall Meeting Stefanovsky, S. V., Yudintsev, S. V., Nikonov, B. S., OMELIANENKO, B. I., Gorshkov, A. I., Sivtsov, A. V., Lapina, M. I., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 27–34
  • Solid solutions of Ce, U, and Th in zircon 100th Annual Meeting of the American-Ceramic-Society Ushakov, S. V., Gong, W., Yagovkina, M. M., Helean, K. B., Lutze, W., Ewing, R. C. AMER CERAMIC SOC. 1999: 357–363
  • Distribution and solubility of radionuclides in waste forms for disposition of plutonium and spent nuclear fuels: Preliminary results 100th Annual Meeting of the American-Ceramic-Society Feng, X., Li, H., Davis, L. L., Li, L., Darab, J. G., Schweiger, M. J., Vienna, J. D., Bunker, B. C., Allen, P. G., Bucher, J. J., Craig, I. M., Edelstein, N. M., Shuh, D. K., Ewing, R. C., Wang, L. M., Vance, E. R. AMER CERAMIC SOC. 1999: 409–419
  • Radiation effects in zircon, hafnon, and thorite: Implications for Pu disposal Symposium on Microstructural Processes in Irradiated Materials, at the 1998 Fall MRS Meeting Meldrum, A., Zinkle, S. J., Boatner, L. A., Wu, M., Mu, R., Ueda, A., Henderson, D. O., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 395–400
  • The effect of temperature and damage energy on amorphization in zircon Symposium on Microstructural Processes in Irradiated Materials, at the 1998 Fall MRS Meeting Weber, M. J., Devanathan, R., Meldrum, A., Boatner, L. A., Ewing, R. C., Wang, L. M. MATERIALS RESEARCH SOCIETY. 1999: 367–372
  • Structural contributions to the third-law entropy of uranyl phases 22nd Symposium on Scientific Basis for Nuclear Waste Management held at the 1998 MRS Fall Meeting Chen, F. R., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 1017–1024
  • Radioactivity and the 20th Century REVIEWS IN MINERALOGY <D> Ewing, R. C. 1999; 38: 1-21
  • Zirconia - A ceramic for excess weapons plutonium wastes 22nd Symposium on Scientific Basis for Nuclear Waste Management held at the 1998 MRS Fall Meeting Gong, W. L., Lutze, W., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 63–70
  • Effect of microstructure and chemical bonding on the adhesion strength of a silicon/polymer interface for microelectronic packaging applications Symposium D on Integration of Dissimilar Materials in Micro- and Optoelectronics / Symposium I on III-V and SiGe Group IV Device/IC Processing Challenges for Commercial Applications, at the 1998 MRS Fall Meeting Pantelidis, D., Lee, H. J., Bravman, J. C. MATERIALS RESEARCH SOCIETY. 1999: 165–170
  • Electron irradiation of zeolites Symposium on Microstructural Processes in Irradiated Materials, at the 1998 Fall MRS Meeting Wang, S. X., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1999: 361–366
  • Ion irradiation-induced phase transformation of pyrochlore and zirconolite 11th International Conference on Ion Beam Modification of Materials (IBMM98) Wang, S. X., Wang, L. M., Ewing, R. C., Was, G. S., Lumpkin, G. R. ELSEVIER SCIENCE BV. 1999: 704–9
  • Ion irradiation effects for two pyrochlore compositions: Gd2Ti2O7 and Gd2Zr2O7 Symposium on Microstructural Processes in Irradiated Materials, at the 1998 Fall MRS Meeting Wang, S. X., Wang, L. M., Ewing, R. C., Kutty, K. V. MATERIALS RESEARCH SOCIETY. 1999: 355–360
  • The dissolution rate of chemically durable materials: Zircon 100th Annual Meeting of the American-Ceramic-Society Helean, K. B., Lutze, W., Ewing, R. C. AMER CERAMIC SOC. 1999: 297–304
  • Rubicline, a new feldspar from San Piero in Campo, Elba, Italy AMERICAN MINERALOGIST Teertstra, D. K., Cerny, P., Hawthorne, F. C., Pier, J., Wang, L. M., Ewing, R. C. 1998; 83 (11-12): 1335-1339
  • Cross-sectional transmission electron microscopy study of 1.5 MeV Kr+ irradiation-induced amorphization in alpha-quartz JOURNAL OF APPLIED PHYSICS Gong, W. L., Wang, L. M., Ewing, R. C. 1998; 84 (8): 4204-4208
  • Amorphization of ceramic materials by ion beam irradiation Engineering Foundation Conference on the Modification of Ceramics and Semiconductors by Ion Bombardment Wang, L. M., Wang, S. X., Gong, W. L., Ewing, R. C., Weber, W. J. ELSEVIER SCIENCE SA. 1998: 106–13
  • A transient liquid-like phase in the displacement cascades of zircon, hafnon and thorite NATURE Meldrum, A., Zinkle, S. J., Boatner, L. A., Ewing, R. C. 1998; 395 (6697): 56-58
  • Ion beam-induced amorphization in MgO-Al2O3-SiO2. II. Empirical model JOURNAL OF NON-CRYSTALLINE SOLIDS Wang, S. X., Wang, L. M., Ewing, R. C., Doremus, R. H. 1998; 238 (3): 214-224
  • Ion beam-induced amorphization in MgO-Al2O3-SiO2. I. Experimental and theoretical basis JOURNAL OF NON-CRYSTALLINE SOLIDS Wang, S. X., Wang, L. M., Ewing, R. C., Doremus, R. H. 1998; 238 (3): 198-213
  • Radiation damage in zircon and monazite GEOCHIMICA ET COSMOCHIMICA ACTA Meldrum, A., Boatner, L. A., Weber, W. J., Ewing, R. C. 1998; 62 (14): 2509-2520
  • The role of pe, pH, and carbonate on the solubility of UO2 and uraninite under nominally reducing conditions GEOCHIMICA ET COSMOCHIMICA ACTA Casas, I., de Pablo, J., Gimenez, J., Torrero, M. E., Bruno, J., Cera, E., Finch, R. J., Ewing, R. C. 1998; 62 (13): 2223-2231
  • A method to predict free energies of formation of mineral phases in the U(VI)-SiO2-H2O system Actinides-97 Conference Clark, S. B., Ewing, R. C., Schaumloffel, J. C. ELSEVIER SCIENCE SA. 1998: 189–193
  • Radiation effects in crystalline ceramics for the immobilization of high-level nuclear waste and plutonium JOURNAL OF MATERIALS RESEARCH Weber, W. J., Ewing, R. C., Catlow, C. R., de la Rubia, T. D., Hobbs, L. W., Kinoshita, C., Matzke, H., Motta, A. T., Nastasi, M., Salje, E. K., Vance, E. R., Zinkle, S. J. 1998; 13 (6): 1434-1484
  • Structural relations among schoepite, metaschoepite and "dehydrated schoepite" CANADIAN MINERALOGIST Finch, R. J., Hawthorne, F. C., Ewing, R. C. 1998; 36: 831-845
  • Ion irradiation-induced amorphization of CaA1(2)O(4) 9th International Conference on Radiation Effects in Insulators (REI-9) Wang, S. X., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 1998: 509–13
  • Temperature dependence of Kr ion-induced amorphization of mica minerals 9th International Conference on Radiation Effects in Insulators (REI-9) Wang, L. M., Wang, S. X., Gong, W. L., Ewing, R. C. ELSEVIER SCIENCE BV. 1998: 501–8
  • Effects of ionizing and displacive irradiation on several perovskite-structure oxides 9th International Conference on Radiation Effects in Insulators (REI-9) Meldrum, A., Boatner, L. A., Ewing, R. C. ELSEVIER SCIENCE BV. 1998: 347–52
  • Analytical electron microscopy study of surface layers formed on the French SON68 nuclear waste glass during vapor hydration at 200 degrees C JOURNAL OF NUCLEAR MATERIALS Gong, W. L., Wang, L. M., Ewing, R. C., Vernaz, E., Bates, J. K., Ebert, W. L. 1998; 254 (2-3): 249-265
  • The Hawley Medal for 1997 to Peter C. Burns, Mark L. Miller and Rodney C. Ewing CANADIAN MINERALOGIST Ewing, R. C. 1998; 36: 240-240
  • Transmission electron microscopy study of radiation effects in materials for nuclear waste disposal 14th International Congress on Electron Microscopy Wang, L. M., Ewing, R. C. IOP PUBLISHING LTD. 1998: 825–826
  • Vitrification of high-level radioactive waste by sintering under pressure 21st International Symposium on the Scientific Basis for Nuclear Waste Management Lutze, W., Gong, W., Abdelouas, A., Ewing, R. C., Scales, C. MATERIALS RESEARCH SOCIETY. 1998: 223–230
  • The crystal chemistry of hexavalent uranium: Polyhedron geometries, bond-valence parameters, and polymerization of polyhedra CANADIAN MINERALOGIST Burns, P. C., Ewing, R. C., Hawthorne, F. C. 1997; 35: 1551-1570
  • Distinguishing among schoepite, [(UO2)(8)O-2(OH)(12)](H2O)(12), and related minerals by X-ray powder diffraction POWDER DIFFRACTION Finch, R. J., Hawthorne, F. C., Miller, M. L., Ewing, R. C. 1997; 12 (4): 230-238
  • The kinetics of alpha-decay-induced amorphization in zircon and apatite containing weapons-grade plutonium or other actinides JOURNAL OF NUCLEAR MATERIALS Weber, W. J., Ewing, R. C., Meldrum, A. 1997; 250 (2-3): 147-155
  • Displacive radiation effects in the monazite- and zircon-structure orthophosphates PHYSICAL REVIEW B Meldrum, A., Boatner, L. A., Ewing, R. C. 1997; 56 (21): 13805-13814
  • The crystal structure of ianthinite, [U-2(4+)(UO2)(4)O-6(OH)(4)(H2O)(4)](H2O)(5): a possible phase for Pu4+ incorporation during the oxidation of spent nuclear fuel JOURNAL OF NUCLEAR MATERIALS Burns, P. C., Finch, R. J., Hawthorne, F. C., Miller, M. L., Ewing, R. C. 1997; 249 (2-3): 199-206
  • Characterization and dissolution behavior of a becquerelite from Shinkolobwe, Zaire GEOCHIMICA ET COSMOCHIMICA ACTA Casas, I., Bruno, J., Cera, E., Finch, R. J., Ewing, R. C. 1997; 61 (18): 3879-3884
  • Electron-irradiation-induced phase segregation in crystalline and amorphous apatite: A TEM study AMERICAN MINERALOGIST Meldrum, A., Wang, L. M., Ewing, R. C. 1997; 82 (9-10): 858-869
  • Mineral chemistry and oxygen isotopic analyses of uraninite, pitchblende and uranium alteration minerals from the Cigar Lake deposit, Saskatchewan, Canada APPLIED GEOCHEMISTRY Fayek, M., Janeczek, J., Ewing, R. C. 1997; 12 (5): 549-565
  • Radiation effects in glasses used for immobilization of high-level waste and plutonium disposition JOURNAL OF MATERIALS RESEARCH Weber, W. J., Ewing, R. C., Angell, C. A., Arnold, G. W., Cormack, A. N., Delaye, J. M., Griscom, D. L., Hobbs, L. W., NAVROTSKY, A., Price, D. L., Stoneham, A. M., Weinberg, W. C. 1997; 12 (8): 1946-1978
  • Electron-irradiation-induced nucleation and growth in amorphous LaPO4, ScPO4, and zircon JOURNAL OF MATERIALS RESEARCH Meldrum, A., Boatner, L. A., Ewing, R. C. 1997; 12 (7): 1816-1827
  • Ion beam-irradiation induced structure transformation in alpha-AlMnSi 10th International Conference on Ion Beam Modification of Materials (IBMM-96) Guo, Y. X., Wang, L. M., Chen, L. F., Ewing, R. C. ELSEVIER SCIENCE BV. 1997: 752–755
  • Donathite discredited: A mixture of two spinels NEUES JAHRBUCH FUR MINERALOGIE-MONATSHEFTE Burns, P. C., Hawthorne, F. C., Libowitzky, E., Bordes, N., Ewing, R. C. 1997: 163-174
  • Ion-beam-induced amorphization of LaPO4 and ScPO4 10th International Conference on Ion Beam Modification of Materials (IBMM-96) Meldrum, A., Boatner, L. A., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 1997: 160–165
  • Ion irradiation-induced phase transformation in Al-Cu-Co-Ge decagonal quasicrystal 10th International Conference on Ion Beam Modification of Materials (IBMM-96) Chen, L. F., Wang, L. M., Guo, Y. X., Ewing, R. C. ELSEVIER SCIENCE BV. 1997: 127–131
  • Incorporation mechanisms of actinide elements into the structures of U6+ phases formed during the oxidation of spent nuclear fuel JOURNAL OF NUCLEAR MATERIALS Burns, P. C., Ewing, R. C., Miller, M. L. 1997; 245 (1): 1-9
  • Clarkeite: New chemical and structural data AMERICAN MINERALOGIST Finch, R. J., Ewing, R. C. 1997; 82 (5-6): 607-619
  • Amorphization of Al2SiO5 polymorphs under ion beam irradiation 10th International Conference on Ion Beam Modification of Materials (IBMM-96) Wang, S. X., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 1997: 186–190
  • Interface-mediated amorphization of coesite by 200 keV electron irradiation JOURNAL OF APPLIED PHYSICS Gong, W. L., Wang, L. M., Ewing, R. C., Xie, H. S. 1997; 81 (6): 2570-2574
  • Disposing of plutonium SCIENCE Ewing, R. C., Lutze, W. 1997; 275 (5301): 737-737
  • Ion irradiation-induced amorphization in the Al2O3-SiO2 system: A comparison with glass formation JOURNAL OF APPLIED PHYSICS Wang, S. X., Wang, L. M., Ewing, R. C., Doremus, R. H. 1997; 81 (2): 587-593
  • Transuranium element incorporation into the beta-U3O8 uranyl sheet Symposium on Scientific Basis for Nuclear Waste Management XX Miller, M. L., Burns, P. C., Finch, R. J., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1997: 581–588
  • Uraninite: A 2 GA spent nuclear fuel from the natural fission reactor at Bangombe in Gabon, West Africa Symposium on Scientific Basis for Nuclear Waste Management XX Jensen, K. A., Ewing, R. C., GAUTHIERLAFAYE, F. MATERIALS RESEARCH SOCIETY. 1997: 1209–1218
  • Ion irradiation-induced amorphization in the MgO-Al2O3-SiO2 system: A cascade quenching model Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting Wang, S. X., Wang, L. M., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1997: 619–624
  • Electron-irradiation-induced crystallization orthophosphates Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting Meldrum, A., Boatner, L. A., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1997: 697–702
  • Transmission electron microscopy study of alpha-decay damage in aeschynite and britholite Symposium on Scientific Basis for Nuclear Waste Management XX Gong, W. L., Wang, L. M., Ewing, R. C., Chen, L. F., Lutze, W. MATERIALS RESEARCH SOCIETY. 1997: 649–656
  • Uraninite-water interactions in an oxidizing environment Symposium on Scientific Basis for Nuclear Waste Management XX Fayek, M., Kyser, T. K., Ewing, R. C., Miller, M. L. MATERIALS RESEARCH SOCIETY. 1997: 1201–1208
  • Amorphization of ceramic materials by ion-beam-irradiation: Parallels to glass formation Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting Wang, L. M., Wang, S. X., Gong, W. L., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1997: 583–594
  • Mineralogical and microtextural characterization of ''gel-zircon'' from the Manibay uranium mine, Kazakhstan Symposium on Scientific Basis for Nuclear Waste Management XX Helean, K. B., Burakov, B. E., Anderson, E. B., Strykanova, E. E., Ushakov, S. V., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1997: 1219–1226
  • Description and classification of uranium oxide hydrate sheet anion topologies JOURNAL OF MATERIALS RESEARCH Miller, M. L., Finch, R. J., Burns, P. C., Ewing, R. C. 1996; 11 (12): 3048-3056
  • Uraninite and UO2 in spent nuclear fuel: A comparison Proceedings of the Spent Fuel Workshop Janeczek, J., Ewing, R. C., Oversby, V. M., Werme, L. O. ELSEVIER SCIENCE BV. 1996: 121–30
  • The crystal structure of schoepite, [(UO2)(8)O-2(OH)(12)](H2O)(12) CANADIAN MINERALOGIST Finch, R. J., Cooper, M. A., Hawthorne, F. C., Ewing, R. C. 1996; 34: 1071-1088
  • Geochemical alteration of pyrochlore group minerals: Betafite subgroup AMERICAN MINERALOGIST Lumpkin, G. R., Ewing, R. C. 1996; 81 (9-10): 1237-1248
  • Florencite-(La) with fissiogenic REEs from a natural fission reactor at Bangombe, Gabon AMERICAN MINERALOGIST Janeczek, J., Ewing, R. C. 1996; 81 (9-10): 1263-1269
  • Temperature dependent microstructural modification in ion-irradiated Tl-type high temperature superconductors PHYSICA C Newcomer, P. P., Barbour, J. C., Wang, L. M., Venturini, E. L., KWAK, J. F., Ewing, R. C., Miller, M. L., Morosin, B. 1996; 267 (3-4): 243-253
  • U6+ minerals and inorganic phases: A comparison and hierarchy of crystal structures CANADIAN MINERALOGIST Burns, P. C., Miller, M. L., Ewing, R. C. 1996; 34: 845-880
  • Irradiation-induced amorphization of AlPO4 8th International Conference on Radiation Effects in Insulators (REI-8) - Beam Interactions with Materials and Atoms SREERAM, A. N., Hobbs, L. W., Bordes, N., Ewing, R. C. ELSEVIER SCIENCE BV. 1996: 126–30
  • Electron-irradiation- and ion-beam-induced amorphization of coesite PHYSICAL REVIEW B Gong, W. L., Wang, L. M., Ewing, R. C., Zhang, J. 1996; 54 (6): 3800-3808
  • Phosphatian coffinite with rare earth elements and Ce-rich francoisite-(Nd) from sandstone beneath a natural fission reactor at Bangombe, Gabon MINERALOGICAL MAGAZINE Janeczek, J., Ewing, R. 1996; 60 (401): 665-669
  • Ion beam induced amorphization of monazite 8th International Conference on Radiation Effects in Insulators (REI-8) - Beam Interactions with Materials and Atoms Meldrum, A., Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 1996: 220–24
  • Surface and grain-boundary amorphization: Thermodynamic melting of coesite below the glass transition temperature PHYSICAL REVIEW B Gong, W. L., Wang, L. M., Ewing, R. C., Fei, Y. 1996; 53 (5): 2155-2158
  • On the roles of temperature and interfaces in irradiation and thermally induced solid state amorphization Symposium C on Thermodynamics and Kinetics of Phase Transformations, at the 1995 MRS Fall Meeting Wang, L. M., Gong, W. L., Ewing, R. C., Weber, W. J. MATERIALS RESEARCH SOC. 1996: 233–238
  • Schoepite and dehydrated schoepite Symposium on Scientific Basis for Nuclear Waste Management XIX, at the 1995 MRS Fall Meeting Finch, R. J., Hawthorne, F. C., Ewing, R. C. MATERIALS RESEARCH SOC. 1996: 361–368
  • Description and classification of uranium oxide hydrate sheet topologies Symposium on Scientific Basis for Nuclear Waste Management XIX, at the 1995 MRS Fall Meeting Miller, M. L., Finch, R. J., Burns, P. C., Ewing, R. C. MATERIALS RESEARCH SOC. 1996: 369–376
  • Aeschynite and euxenite structure-types as host phases for rare-earths and actinides from HLW Symposium on Scientific Basis for Nuclear Waste Management XIX, at the 1995 MRS Fall Meeting Gong, W. L., Ewing, R. C., Wang, L. M., Xie, H. S. MATERIALS RESEARCH SOC. 1996: 377–384
  • A comparative study on ion-beam induced effects in spinel structure types 9th International Conference on Ion Beam Modification of Materials (IBMM 95) Wang, L. M., Gong, W. L., Bordes, N., Ewing, R. C. ELSEVIER SCIENCE BV. 1996: 1073–1076
  • Clays at the natural nuclear reactor at Bangombe, Gabon: Migration of actinides RADIOCHIMICA ACTA Eberly, P. O., Ewing, R. C., Janeczek, J., Furlano, A. 1996; 74: 271-275
  • Secondary phase formation and the microstructural evolution of surface layers during vapor phase alteration of the French SON68 nuclear waste glass at 200 degrees C Symposium on Scientific Basis for Nuclear Waste Management XIX, at the 1995 MRS Fall Meeting Gong, W. L., Ewing, R. C., Wang, L. M., Vernaz, E., Bates, J. K., Ebert, W. L. MATERIALS RESEARCH SOC. 1996: 197–204
  • STRUCTURAL DAMAGE IN SPINEL AFTER ION IRRADIATION 17th International Symposium on the Effects of Radiation on Materials Bordes, N., Sickafus, K. E., Cooper, E. A., Ewing, R. C. ELSEVIER SCIENCE BV. 1995: 318–323
  • GEOCHEMICAL ALTERATION OF PYROCHLORE GROUP MINERALS - PYROCHLORE SUBGROUP AMERICAN MINERALOGIST Lumpkin, G. R., Ewing, R. C. 1995; 80 (7-8): 732-743
  • RECOIL REFINEMENTS - IMPLICATIONS FOR THE AR-40/AR-39 DATING TECHNIQUE GEOCHIMICA ET COSMOCHIMICA ACTA Onstott, T. C., Miller, M. L., Ewing, R. C., Arnold, G. W., Walsh, D. S. 1995; 59 (9): 1821-1834
  • MECHANISMS OF LEAD RELEASE FROM URANINITE IN THE NATURAL FISSION REACTORS IN GABON GEOCHIMICA ET COSMOCHIMICA ACTA Janeczek, J., Ewing, R. C. 1995; 59 (10): 1917-1931
  • ION-BEAM-INDUCED DISORDERING AND ONSET OF AMORPHIZATION IN SPINEL BY DEFECT ACCUMULATION JOURNAL OF MATERIALS RESEARCH Bordes, N., Wang, L. M., Ewing, R. C., Sickafus, K. E. 1995; 10 (4): 981-985
  • ZIRCON - A HOST-PHASE FOR THE DISPOSAL OF WEAPONS PLUTONIUM JOURNAL OF MATERIALS RESEARCH Ewing, R. C., Lutze, W., Weber, W. J. 1995; 10 (2): 243-246
  • Application of channeling techniques and high resolution transmission electron microscopy to ion-beam damaged zircon Symposium on Microstructure of Irradiated Materials, at the 1994 MRS Fall Meeting Bordes, N., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1995: 371–376
  • ILLITE IN THE OKLO NATURAL FISSION REACTORS IN GABON - CONSIDERATIONS FOR CS CONTAINMENT 18th International Symposium on the Scientific Basis for Nuclear Waste Management Szabo, G., Guczi, J., Nagy, B., Janeczek, J., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1995: 1203–1210
  • PREDICTION OF UNKNOWN URANYL OXIDE HYDRATE STRUCTURE TYPES - COMPARISON OF CALCULATED AND MEASURED XRD POWDER PATTERNS 18th International Symposium on the Scientific Basis for Nuclear Waste Management Finch, R. J., Hawthorne, F. C., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1995: 653–660
  • TEMPERATURE DEPENDENCE OF AMORPHIZATION FOR ZIRCONOLITE AND PEROVSKITE IRRADIATED WITH 1 MEV KRYPTON IONS 18th International Symposium on the Scientific Basis for Nuclear Waste Management White, T. J., Ewing, R. C., Wang, L. M., Forrester, J. S., Montross, C. MATERIALS RESEARCH SOCIETY. 1995: 1413–1420
  • Effects of ion dose and irradiation temperature on the microstructure of three spinel compositions Symposium on Microstructure of Irradiated Materials, at the 1994 MRS Fall Meeting Wang, L. M., Gong, W. L., Bordes, N., Ewing, R. C., Fei, Y. MATERIALS RESEARCH SOCIETY. 1995: 407–412
  • CRICHTONITE STRUCTURE TYPE (AM21O38 AND A2M19O36) AS A HOST PHASE IN CRYSTALLINE WASTE FROM CERAMICS 18th International Symposium on the Scientific Basis for Nuclear Waste Management Gong, W. L., Ewing, R. C., Wang, L. M., Xie, H. S. MATERIALS RESEARCH SOCIETY. 1995: 807–815
  • Ion-beam and electron-beam induced amorphization of berlinite (A1PO(4)) Symposium on Microstructure of Irradiated Materials, at the 1994 MRS Fall Meeting Bordes, N., Ewing, R. C. MATERIALS RESEARCH SOCIETY. 1995: 395–400
  • Amorphization of complex ceramics by heavy-particle irradiations Symposium on Microstructure of Irradiated Materials, at the 1994 MRS Fall Meeting Ewing, R. C., Wang, L. M., Weber, W. J. MATERIALS RESEARCH SOCIETY. 1995: 347–358
  • PRECIPITATION OF URANINITE IN CHLORITE-BEARING VEINS OF THE HYDROTHERMAL ALTERATION ZONE (ARGILE-DE-PILE) OF THE NATURAL NUCLEAR REACTOR AT BANGOMBE, REPUBLIC OF GABON 18th International Symposium on the Scientific Basis for Nuclear Waste Management EBERLY, P., Janeczek, J., Ewing, R. MATERIALS RESEARCH SOCIETY. 1995: 1195–1202
  • MATERIALS SCIENCE OF RADIOACTIVE-WASTE FORMS MRS BULLETIN Ewing, R. C., Lutze, W. 1994; 19 (12): 16-18
  • RADIATION EFFECTS IN CERAMICS International Summer School on the Fundamentals of Radiation Damage Hobbs, L. W., CLINARD, F. W., Zinkle, S. J., Ewing, R. C. ELSEVIER SCIENCE BV. 1994: 291–321
  • ENERGETICS OF RADIATION-DAMAGE IN NATURAL ZIRCON (ZRSIO4) PHYSICS AND CHEMISTRY OF MINERALS Ellsworth, S., NAVROTSKY, A., Ewing, R. C. 1994; 21 (3): 140-149
  • THE RADIATION-INDUCED CRYSTALLINE-TO-AMORPHOUS TRANSITION IN ZIRCON JOURNAL OF MATERIALS RESEARCH Weber, W. J., Ewing, R. C., Wang, L. M. 1994; 9 (3): 688-698
  • IN-SITU TEM OBSERVATION OF RADIATION-INDUCED AMORPHIZATION OF CRYSTALS WITH APATITE STRUCTURE Symposium on Hydroxyapatite and Related Compounds, at the Materials-Research-Society Meeting Wang, L. M., Cameron, M., Weber, W. J., Crowley, K. D., Ewing, R. C. CRC PRESS INC. 1994: 243–249
  • FORMATION OF SECONDARY URANIUM MINERALS IN THE KOONGARRA DEPOSIT, AUSTRALIA Symposium on Scientific Basis for Nuclear Waste Management XVII, at the 1993 Fall Meeting of the Materials-Research-Society Isobe, H., Ewing, R. C., Murakami, T. MATERIALS RESEARCH SOC. 1994: 653–660
  • Quantitative analysis of displacement cascade damage in ion irradiated TlBa2CaCu2O7 superconductor by digital HRTEM 13th International Congress on Electron Microscopy Wang, L. M., Newcomer, P. P., Ewing, R. C., Morosin, B. EDITIONS PHYSIQUE. 1994: 957–958
  • AMORPHIZATION AND DYNAMIC RECOVERY OF A2BO4 STRUCTURE TYPES DURING 1.5-MEV KRYPTON ION-BEAM IRRADIATION Symposium on Crystallization and Related Phenomena in Amorphous Materials, at the 1993 Fall Meeting of the Materials-Research-Society Wang, L. M., Gong, W. L., Ewing, R. C. MATERIALS RESEARCH SOC. 1994: 405–410
  • AMORPHIZATION AND DYNAMIC RECOVERY OF A2BO4 STRUCTURE TYPES DURING 1.5 MEV KRYPTON ION-BEAM IRRADIATION Symposium on Materials Synthesis and Processing Using Ion Beams, at the 1993 MRS Fall Meeting Wang, L. M., Gong, W. L., Ewing, R. C. MATERIALS RESEARCH SOC. 1994: 247–252
  • PETROGRAPHIC ANALYSIS OF SAMPLES FROM THE URANIUM DEPOSIT AT OKLO, REPUBLIC OF GABON 4th International Conference on Chemistry and Migratory Behaviour of Actinides and Fission Products EBERLY, P., Janeczek, J., Ewing, R. C. OLDENBOURG VERLAG. 1994: 455–461
  • FORMATION, OXIDATION AND ALTERATION OF IANTHINITE Symposium on Scientific Basis for Nuclear Waste Management XVII, at the 1993 Fall Meeting of the Materials-Research-Society Finch, R. J., Ewing, R. C. MATERIALS RESEARCH SOC. 1994: 625–630
  • Petrographic analysis of samples from the uranium deposit at Oklo, Republic of Gabon 4th International Conference on Chemistry and Migratory Behaviour of Actinides and Fission Products EBERLY, P., Janeczek, J., Ewing, R. C. R OLDENBOURG VERLAG. 1994: 565–571
  • OXIDATION OF URANINITE - DOES TETRAGONAL U3O7 OCCUR IN NATURE JOURNAL OF NUCLEAR MATERIALS Janeczek, J., Ewing, R. C., Thomas, L. E. 1993; 207: 177-191
  • THE STRUCTURE OF APERIODIC, METAMICT (CA,TH)ZRTI2O7 (ZIRCONOLITE) - AN EXAFS STUDY OF THE ZR-SITES, TH-SITES AND U-SITES JOURNAL OF MATERIALS RESEARCH Farges, F., Ewing, R. C., Brown, G. E. 1993; 8 (8): 1983-1995
  • HRTEM STUDY OF DISPLACEMENT CASCADE DAMAGE IN KRYPTON-ION-IRRADIATED SILICATE OLIVINE 4TH CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE Wang, L. M., Miller, M. L., Ewing, R. C. ELSEVIER SCIENCE BV. 1993: 339–47
  • METAMICT AND CHEMICALLY ALTERED VESUVIANITE CANADIAN MINERALOGIST Eby, R. K., Janeczek, J., Ewing, R. C., Ercit, T. S., Groat, L. A., Chakoumakos, B. C., Hawthorne, F. C., Rossman, G. R. 1993; 31: 357-369
  • ION IRRADIATION-INDUCED NANO-SCALE POLYCRYSTALLIZATION OF INTERMETALLIC AND CERAMIC MATERIALS 8TH INTERNATIONAL CONF ON ION BEAM MODIFICATION OF MATERIALS Wang, L. M., BIRTCHER, R. C., Ewing, R. C. ELSEVIER SCIENCE BV. 1993: 1109–1113
  • CRYSTAL-CHEMISTRY OF SAMARSKITE AMERICAN MINERALOGIST Warner, J. K., Ewing, R. C. 1993; 78 (3-4): 419-424
  • MINERALOGY GEOTIMES Ewing, R. C. 1993; 38 (2): 31-32
  • IMAGE SIMULATION OF PARTIALLY AMORPHOUS MATERIALS ULTRAMICROSCOPY Miller, M. L., Ewing, R. C. 1993; 48 (1-2): 203-237
  • THE AMORPHIZATION OF COMPLEX SILICATES BY ION-BEAM IRRADIATION JOURNAL OF MATERIALS RESEARCH Eby, R. K., Ewing, R. C., BIRTCHER, R. C. 1992; 7 (11): 3080-3102
  • THEMATIC ISSUE ON NUCLEAR WASTE - PREFACE JOURNAL OF NUCLEAR MATERIALS Ewing, R. C. 1992; 190: R7-R10
  • DISSOLUTION AND ALTERATION OF URANINITE UNDER REDUCING CONDITIONS JOURNAL OF NUCLEAR MATERIALS Janeczek, J., Ewing, R. C. 1992; 190: 157-173
  • THE CORROSION OF URANINITE UNDER OXIDIZING CONDITIONS JOURNAL OF NUCLEAR MATERIALS Finch, R. J., Ewing, R. C. 1992; 190: 133-156
  • ALTERATION OF URANIUM MINERALS IN THE KOONGARRA DEPOSIT, AUSTRALIA - UNWEATHERED ZONE JOURNAL OF NUCLEAR MATERIALS Isobe, H., Murakami, T., Ewing, R. C. 1992; 190: 174-187
  • STRUCTURAL FORMULA OF URANINITE JOURNAL OF NUCLEAR MATERIALS Janeczek, J., Ewing, R. C. 1992; 190: 128-132
  • EARTH MATERIALS MRS BULLETIN Ewing, R. C., NAVROTSKY, A. 1992; 17 (5): 19-20
  • ION-BEAM-INDUCED AMORPHIZATION OF COMPLEX CERAMIC MATERIALS MINERALS MRS BULLETIN Wang, L. M., Ewing, R. C. 1992; 17 (5): 38-44
  • DETAILED INSITU STUDY OF ION BEAM-INDUCED AMORPHIZATION OF ZIRCON 6TH INTERNATIONAL CONF ON RADIATION EFFECTS IN INSULATORS Wang, L. M., Ewing, R. C. ELSEVIER SCIENCE BV. 1992: 324–29
  • AMORPHIZATION OF ZIRCONOLITE - ALPHA-DECAY EVENT DAMAGE VERSUS KRYPTON ION IRRADIATION 6TH INTERNATIONAL CONF ON RADIATION EFFECTS IN INSULATORS Ewing, R. C., Wang, L. M. ELSEVIER SCIENCE BV. 1992: 319–23
  • GEOCHEMICAL ALTERATION OF PYROCHLORE GROUP MINERALS - MICROLITE SUBGROUP AMERICAN MINERALOGIST Lumpkin, G. R., Ewing, R. C. 1992; 77 (1-2): 179-188
  • COMPARISON OF INSITU AND LABORATORY CORROSION EXPERIMENTS WITH BOROSILICATE NUCLEAR WASTE GLASS 15TH INTERNATIONAL SYMP ON THE SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT, AT THE 1991 FALL MEETING OF THE EUROPEAN MATERIALS RESEARCH SOC Lutze, W., Ewing, R. C. MATERIALS RESEARCH SOC. 1992: 127–134
  • COFFINITIZATION - A MECHANISM FOR THE ALTERATION OF UO2 UNDER REDUCING CONDITIONS 15TH INTERNATIONAL SYMP ON THE SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT, AT THE 1991 FALL MEETING OF THE EUROPEAN MATERIALS RESEARCH SOC Janeczek, J., Ewing, R. C. MATERIALS RESEARCH SOC. 1992: 497–504
  • WEATHERING OF NATURAL URANYL OXIDE HYDRATES - SCHOEPITE POLYTYPES AND DEHYDRATION EFFECTS RADIOCHIMICA ACTA Finch, R. J., Miller, M. L., Ewing, R. C. 1992; 58-9: 433-443
  • STORED ENERGY IN NATURAL ZIRCONOLITE AND ITS SYNTHETIC COUNTERPART AFTER ALPHA-RECOIL SELF-IRRADIATION DAMAGE JOURNAL OF NUCLEAR MATERIALS CLINARD, F. W., Foltyn, E. M., Ewing, R. C. 1991; 185 (2): 202-207
  • X-RAY-POWDER DIFFRACTION STUDY OF ANNEALED URANINITE JOURNAL OF NUCLEAR MATERIALS Janeczek, J., Ewing, R. C. 1991; 185 (1): 66-77
  • ALPHA-DECAY EVENT DAMAGE IN ZIRCON AMERICAN MINERALOGIST Murakami, T., Chakoumakos, B. C., Ewing, R. C., Lumpkin, G. R., Weber, W. J. 1991; 76 (9-10): 1510-1532
  • INSITU TEM STUDY OF ION-BEAM-INDUCED AMORPHIZATION OF COMPLEX SILICATE STRUCTURES 7TH INTERNATIONAL CONF ON ION BEAM MODIFICATION OF MATERIALS ( IBMM 90 ) Wang, L. M., Eby, R. K., Janeczek, J., Ewing, R. C. ELSEVIER SCIENCE BV. 1991: 395–400
  • ACCUMULATION OF STRUCTURAL DEFECTS IN ION-IRRADIATED CA2ND8(SIO4)6O2 JOURNAL OF MATERIALS RESEARCH Weber, W. J., Eby, R. K., Ewing, R. C. 1991; 6 (6): 1334-1345
  • ALPHA-DECAY DAMAGE IN TITANITE AMERICAN MINERALOGIST Hawthorne, F. C., Groat, L. A., Raudsepp, M., Ball, N. A., Kimata, M., SPIKE, F. D., GABA, R., Halden, N. M., Lumpkin, G. R., Ewing, R. C., Greegor, R. B., Lytle, F. W., Ercit, T. S., Rossman, G. R., Wicks, F. J., Ramik, R. A., Sherriff, B. L., Fleet, M. E., Mccammon, C. 1991; 76 (3-4): 370-396
  • ALPHA-RECOIL DAMAGE IN TITANITE (CATISIO5) - DIRECT OBSERVATION AND ANNEALING STUDY USING HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY JOURNAL OF MATERIALS RESEARCH Lumpkin, G. R., Eby, R. K., Ewing, R. C. 1991; 6 (3): 560-564
  • INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES ESTABLISHED MRS BULLETIN Ewing, R. C. 1991; 16 (2): 33-33
  • HARDNESS AND ELASTIC-MODULUS OF ZIRCON AS A FUNCTION OF HEAVY-PARTICLE IRRADIATION DOSE .1. INSITU ALPHA-DECAY EVENT DAMAGE RADIATION EFFECTS AND DEFECTS IN SOLIDS Chakoumakos, B. C., OLIVER, W. C., Lumpkin, G. R., Ewing, R. C. 1991; 118 (4): 393-403
  • HIGH-TEMPERATURE ANNEALING OF NATURAL UO2+X 14TH INTERNATIONAL SYMP ON THE SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT Janeczek, J., Ewing, R. C. MATERIALS RESEARCH SOC. 1991: 235–240
  • HIGH-LEVEL NUCLEAR WASTE IMMOBILIZATION WITH CERAMICS WORLD CONGRESS ON HIGH TECH CERAMICS ( 7TH CIMTEC ) Ewing, R. C., Lutze, W. ELSEVIER SCI LTD. 1991: 287–93
  • ALTERATION OF NATURAL UO2 UNDER OXIDIZING CONDITIONS FROM SHINKOLOBWE, KATANGA, ZAIRE - A NATURAL ANALOG FOR THE CORROSION OF SPENT FUEL RADIOCHIMICA ACTA Finch, R. J., Ewing, R. C. 1991; 52-3: 395-401
  • PB-IMPLANTED SRTIO3 ANALYZED USING RUTHERFORD BACKSCATTERING AND SURFACE SENSITIVE EXAFS XANES SPECTROSCOPY JOURNAL OF NON-CRYSTALLINE SOLIDS Greegor, R. B., Lytle, F. W., Arnold, G. W., Ewing, R. C. 1990; 122 (2): 121-132
  • CHEMICAL CORROSION OF HIGHLY RADIOACTIVE BOROSILICATE NUCLEAR WASTE GLASS UNDER SIMULATED REPOSITORY CONDITIONS JOURNAL OF MATERIALS RESEARCH Werme, L., BJORNER, I. K., Bart, G., ZWICKY, H. U., Grambow, B., Lutze, W., Ewing, R. C., MAGRABI, C. 1990; 5 (5): 1130-1146
  • ANNEALING OF ALPHA-RECOIL DAMAGE IN NATURAL TITANITE, CATISIO5 SYMP AT THE 1990 SPRING MEETING OF THE MATERIALS RESEARCH SOC : HIGH RESOLUTION ELECTRON MICROSCOPY OF DEFECTS IN MATERIALS Eby, R. K., Ewing, R. C. MATERIALS RESEARCH SOC. 1990: 297–300
  • COMPARISON OF SURFACE-LAYERS FORMED ON SYNTHETIC BASALTIC GLASS, FRENCH R7T7 AND HMI BOROSILICATE NUCLEAR WASTE FORM GLASSES - MATERIALS INTERFACE INTERACTIONS TESTS, WASTE ISOLATION PILOT-PLANT 13TH INTERNATIONAL SYMP AT THE 1989 FALL MEETING OF THE MATERIALS RESEARCH SOC : SCIENTIFIC BASIC FOR NUCLEAR WASTE MANAGEMENT Jercinovic, M. J., KASER, S. A., Ewing, R. C., Lutze, W. MATERIALS RESEARCH SOC. 1990: 355–362
  • APPLICATION OF VARIOUS XAFS TECHNIQUES TO THE INVESTIGATION OF STRUCTURALLY DAMAGED MATERIALS PHYSICA B-CONDENSED MATTER Greegor, R. B., Lytle, F. W., Chakoumakos, B. C., Ewing, R. C., LIVAK, R. J., CLINARD, F. W., Crozier, E. D., Alberding, N., SEARY, A. J., Arnold, G. W., Weber, M. J., Wong, J., Weber, W. J. 1989; 158 (1-3): 498-500
  • METAMICT MINERALS - NATURAL ANALOGS FOR RADIATION-DAMAGE EFFECTS IN CERAMIC NUCLEAR WASTE FORMS NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Ewing, R. C., Chakoumakos, B. C., Lumpkin, G. R., Murakami, T., Greegor, R. B., Lytle, F. W. 1988; 32 (1-4): 487-497
  • PREFERENTIAL LEACHING AND NATURAL ANNEALING OF ALPHA-RECOIL TRACKS IN METAMICT BETAFITE AND SAMARSKITE JOURNAL OF MATERIALS RESEARCH Lumpkin, G. R., Ewing, R. C., Eyal, Y. 1988; 3 (2): 357-368
  • ALPHA-DECAY DAMAGE IN MINERALS OF THE PYROCHLORE GROUP PHYSICS AND CHEMISTRY OF MINERALS Lumpkin, G. R., Ewing, R. C. 1988; 16 (1): 2-20
  • ALPHA-DECAY INDUCED FRACTURING IN ZIRCON - THE TRANSITION FROM THE CRYSTALLINE TO THE METAMICT STATE SCIENCE Chakoumakos, B. C., Murakami, T., Lumpkin, G. R., Ewing, R. C. 1987; 236 (4808): 1556-1559

    Abstract

    A natural single crystal of zircon, ZrSiO(4,) from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 10(16) and 0.8 x 10(16) alpha-events per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 10(16) alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.

    View details for Web of Science ID A1987H781800025

    View details for PubMedID 17835739

  • Alpha-recoil damage in zirconolite (CaZrTi2O7) JOURNAL OF MATERIALS RESEARCH Lumpkin, G. R., Ewing, R. C., Chakoumakos, B. C., Greegor, R. B., Lytle, F. W., Foltyn, E. M., Clinard, F. W., Boatner, L. A., Abraham, M. M. 1986; 1 (4): 564-576
  • THERMAL RECRYSTALLIZATION OF ALPHA-RECOIL DAMAGED MINERALS OF THE PYROCHLORE STRUCTURE TYPE JOURNAL OF NUCLEAR MATERIALS Lumpkin, G. R., Foltyn, E. M., Ewing, R. C. 1986; 139 (2): 113-120
  • JAHNS,R.H. MEMORIAL ISSUE - THE MINERALOGY, PETROLOGY, AND GEOCHEMISTRY OF GRANITIC PEGMATITES AND RELATED GRANITIC-ROCKS - INTRODUCTION AMERICAN MINERALOGIST Brown, G. E., Ewing, R. C. 1986; 71 (3-4): 233-238
  • MEMORIAL OF JAHNS,RICHARD,HENRY MARCH 10, 1915 DECEMBER 31, 1983 AMERICAN MINERALOGIST Brown, G. E., Ewing, R. C. 1986; 71 (3-4): 652-654
  • MINERALOGY AND RADIATION EFFECTS OF MICROLITE FROM THE HARDING PEGMATITE, TAOS COUNTY, NEW-MEXICO AMERICAN MINERALOGIST Lumpkin, G. R., Chakoumakos, B. C., Ewing, R. C. 1986; 71 (3-4): 569-588
  • ALTERATION OF BASALT GLASSES - IMPLICATIONS FOR MODELING THE LONG-TERM STABILITY OF NUCLEAR WASTE GLASSES NATURE Lutze, W., MALOW, G., Ewing, R. C., Jercinovic, M. J., Keil, K. 1985; 314 (6008): 252-255
  • TI-SITE GEOMETRY IN METAMICT, ANNEALED AND SYNTHETIC COMPLEX TI-NB-TA OXIDES BY X-RAY ABSORPTION-SPECTROSCOPY NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Greegor, R. B., Lytle, F. W., Ewing, R. C., HAAKER, R. F. 1984; 1 (2-3): 587-594
  • ALTERATION EFFECTS AND LEACH RATES OF BASALTIC GLASSES - IMPLICATIONS FOR THE LONG-TERM STABILITY OF NUCLEAR WASTE FORM BOROSILICATE GLASSES JOURNAL OF NON-CRYSTALLINE SOLIDS MALOW, G., Lutze, W., Ewing, R. C. 1984; 67 (1-3): 305-321
  • ALPHA-RECOIL DAMAGE IN NATURAL ZIRCONOLITE (CAZRTI2O7) JOURNAL OF NUCLEAR MATERIALS Ewing, R. C., Headley, T. J. 1983; 119 (1): 102-109
  • THE HARDING PEGMATITE - A SUMMARY OF RECENT RESEARCH Chakoumakos, B. C., REGISTER, M. E., BROOKINS, D. G., Ewing, R. C., Landis, G. P. MINERALOGICAL SOC AMER. 1982: 182–83
  • RADIATION-DAMAGE IN NATURAL MATERIALS - ITS IMPLICATIONS FOR RADIOACTIVE-WASTE FORMS Ewing, R. C. AMER INST PHYSICS. 1981: 401–
  • SOLUTION-GELATION METHOD FOR PREPARING POLYCRYSTALLINE ZIRCON JOURNAL OF THE AMERICAN CERAMIC SOCIETY HAAKER, R. F., Ewing, R. C. 1981; 64 (11): C149-C149
  • AMORPHOUS STRUCTURE OF METAMICT MINERALS OBSERVED BY TEM NATURE Headley, T. J., Ewing, R. C., HAAKER, R. F. 1981; 293 (5832): 449-450
  • DIFFERENTIAL THERMAL-ANALYSIS OF SOME IRRADIATED MATERIALS - DISCUSSION AMERICAN MINERALOGIST HAAKER, R. F., Ewing, R. C. 1979; 64 (9-10): 1131-1132
  • METAMICT STATE - RADIATION-DAMAGE IN CRYSTALLINE MATERIALS Ewing, R. C., HAAKER, R. F. AMER CERAMIC SOC. 1979: 326–26
  • CONTRIBUTIONS TO THE MINERAL CHEMISTRY OF HAWAIIAN ROCKS .7. BARIAN-TITANIAN BIOTITES IN NEPHELINITES FROM OAHU, HAWAII AMERICAN MINERALOGIST MANSKER, W. L., Ewing, R. C., Keil, K. 1979; 64 (1-2): 156-159
  • CRYSTAL-STRUCTURES OF THSIO4 POLYMORPHS - HUTTONITE AND THORITE ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE Taylor, M., Ewing, R. C. 1978; 34 (APR): 1074-1079
  • ROWLANDITE FROM BARRINGER HILL RARE-EARTH PEGMATITE DISTRICT, LLANO AND BURNET COUNTIES, TEXAS AMERICAN MINERALOGIST CROOK, W., Ewing, R. C., Ehlmann, A. J. 1978; 63 (7-8): 754-756
  • EUXENITE FROM AMPANGABE, MADAGASCAR CANADIAN MINERALOGIST Ewing, R. C., SNETSINGER, K. G., Bunch, T. E. 1977; 15: 92-96
  • DARAPSKITE, NA3(NO3)(SO4)H2O, A NEW OCCURRENCE, IN TEXAS MINERALOGICAL MAGAZINE Hill, C. A., Ewing, R. C. 1977; 41 (320): 548-550
  • METAMICT COLUMBITE REEXAMINED MINERALOGICAL MAGAZINE Ewing, R. C. 1976; 40 (316): 898-899
  • METAMICT MINERAL ALTERATION - IMPLICATION FOR RADIOACTIVE-WASTE DISPOSAL SCIENCE Ewing, R. C. 1976; 192 (4246): 1336-1337

    Abstract

    Pervasive alteration is a common feature of metamict minerals. Previous studies of metamict niobium-tantalum-titanium oxides and electron microprobe analyses of altered areas in metamict yttrialite document the leaching of uranium, thorium, and rare earth elements. These data suggest that glasses may not provide a stable medium for radioactive waste disposal.

    View details for Web of Science ID A1976BU52900019

    View details for PubMedID 17739840

  • CRYSTAL-CHEMISTRY OF COMPLEX NIOBIUM AND TANTALUM OXIDES .4. METAMICT STATE - DISCUSSION AMERICAN MINERALOGIST Ewing, R. C. 1975; 60 (7-8): 728-733