Robert Sinclair
Charles M. Pigott Professor in the School of Engineering
Materials Science and Engineering
Bio
Using high-resolution transmission electron microscopy, Sinclair studies microelectronic, magnetic thin film microstructure and nanomaterials.
Academic Appointments
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Professor, Materials Science and Engineering
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Member, Bio-X
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Member, Stanford Cancer Institute
Honors & Awards
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Robert Lansing Hardy Gold Medal, The Metallurgical Society of AIME (1976)
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Eli Franklin Burton Award, Electron Microscopy Society of America (1977)
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Fellowship, Alfred P. Sloan Foundation (1979)
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Marcus E. Grossman Award, American Society for Metals (1982)
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Excellence in Undergraduate Teaching, Stanford University Society for Black Scientists and Engineers (1984)
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Excellence in Undergraduate Teaching, Stanford University Society of Chicano/Latino Engineers and Scientists (1993)
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Fellow (inaugural class), Microscopy Society of America (2009)
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Distinguished Scientist, Physical Sciences, Microscopy Society of America (2009)
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David Turnbull Lectureship, Materials Research Society (2012)
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Festschrift in honor of Robert Sinclair and Nestor J. Zaluzec, Ultramicroscopy, volume 176 (2017)
Professional Education
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BA, Cambridge University, Materials Science (1968)
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MA, Cambridge University, Materials Science (1972)
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PhD, Cambridge University, Materials Science (1972)
2024-25 Courses
- Introduction to Materials Science, Nanotechnology Emphasis
ENGR 50, MATSCI 50 (Spr) - Japanese Companies and Japanese Society
ENGR 159Q, MATSCI 159Q (Spr) - Transmission Electron Microscopy
MATSCI 321 (Win) -
Independent Studies (7)
- Graduate Independent Study
MATSCI 399 (Aut, Win, Spr, Sum) - Master's Research
MATSCI 200 (Aut, Win, Spr, Sum) - Participation in Materials Science Teaching
MATSCI 400 (Aut, Win, Spr) - Ph.D. Research
MATSCI 300 (Aut, Win, Spr, Sum) - Practical Training
MATSCI 299 (Aut, Win, Spr, Sum) - Undergraduate Independent Study
MATSCI 100 (Aut, Win, Spr, Sum) - Undergraduate Research
MATSCI 150 (Aut, Win, Spr, Sum)
- Graduate Independent Study
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Prior Year Courses
2023-24 Courses
- Introduction to Materials Science, Nanotechnology Emphasis
ENGR 50 (Spr) - Japanese Companies and Japanese Society
ENGR 159Q, MATSCI 159Q (Spr) - Nanocharacterization of Materials
MATSCI 320 (Win)
2022-23 Courses
- Introduction to Materials Science, Nanotechnology Emphasis
ENGR 50 (Spr) - Japanese Companies and Japanese Society
ENGR 159Q, MATSCI 159Q (Spr) - Transmission Electron Microscopy
MATSCI 321 (Win)
2021-22 Courses
- Introduction to Materials Science, Energy Emphasis
ENGR 50E (Win) - Introduction to Materials Science, Nanotechnology Emphasis
ENGR 50 (Spr) - Japanese Companies and Japanese Society
ENGR 159Q, MATSCI 159Q (Spr) - Nanocharacterization of Materials
MATSCI 320 (Win)
- Introduction to Materials Science, Nanotechnology Emphasis
Stanford Advisees
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Doctoral Dissertation Co-Advisor (AC)
Abby Carbone, Yi Cui, Amy McKeown-Green, Prasanna Sarkar, Chad Serrao -
Master's Program Advisor
Victoria Ganeles, Darshan Mali
All Publications
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Unraveling sources of emission heterogeneity in Silicon Vacancy color centers with cryo-cathodoluminescence microscopy.
Proceedings of the National Academy of Sciences of the United States of America
2024; 121 (14): e2308247121
Abstract
Diamond color centers have proven to be versatile quantum emitters and exquisite sensors of stress, temperature, electric and magnetic fields, and biochemical processes. Among color centers, the silicon-vacancy (SiV[Formula: see text]) defect exhibits high brightness, minimal phonon coupling, narrow optical linewidths, and high degrees of photon indistinguishability. Yet the creation of reliable and scalable SiV[Formula: see text]-based color centers has been hampered by heterogeneous emission, theorized to originate from surface imperfections, crystal lattice strain, defect symmetry, or other lattice impurities. Here, we advance high-resolution cryo-electron microscopy combined with cathodoluminescence spectroscopy and 4D scanning transmission electron microscopy (STEM) to elucidate the structural sources of heterogeneity in SiV[Formula: see text] emission from nanodiamond with sub-nanometer-scale resolution. Our diamond nanoparticles are grown directly on TEM membranes from molecular-level seedings, representing the natural formation conditions of color centers in diamond. We show that individual subcrystallites within a single nanodiamond exhibit distinct zero-phonon line (ZPL) energies and differences in brightness that can vary by 0.1 meV in energy and over 70% in brightness. These changes are correlated with the atomic-scale lattice structure. We find that ZPL blue-shifts result from tensile strain, while ZPL red shifts are due to compressive strain. We also find that distinct crystallites host distinct densities of SiV[Formula: see text] emitters and that grain boundaries impact SiV[Formula: see text] emission significantly. Finally, we interrogate nanodiamonds as small as 40 nm in diameter and show that these diamonds exhibit no spatial change to their ZPL energy. Our work provides a foundation for atomic-scale structure-emission correlation, e.g., of single atomic defects in a range of quantum and two-dimensional materials.
View details for DOI 10.1073/pnas.2308247121
View details for PubMedID 38551833
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Twisted epitaxy of gold nanodisks grown between twisted substrate layers of molybdenum disulfide.
Science (New York, N.Y.)
2024; 383 (6679): 212-219
Abstract
We expand the concept of epitaxy to a regime of "twisted epitaxy" with the epilayer crystal orientation between two substrates influenced by their relative orientation. We annealed nanometer-thick gold (Au) nanoparticles between two substrates of exfoliated hexagonal molybdenum disulfide (MoS2) with varying orientation of their basal planes with a mutual twist angle ranging from 0° to 60°. Transmission electron microscopy studies show that Au aligns midway between the top and bottom MoS2 when the twist angle of the bilayer is small (<~7°). For larger twist angles, Au has only a small misorientation with the bottom MoS2 that varies approximately sinusoidally with twist angle of the bilayer MoS2. Four-dimensional scanning transmission electron microscopy analysis further reveals a periodic strain variation (<|±0.5%|) in the Au nanodisks associated with the twisted epitaxy, consistent with the Moiré registry of the two MoS2 twisted layers.
View details for DOI 10.1126/science.adk5947
View details for PubMedID 38207038
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Twisted Epitaxial Growth of Gold Nanodiscs Confined in Twisted Bilayer Molybdenum Disulfide.
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada
2023; 29 (Supplement_1): 1657-1658
View details for DOI 10.1093/micmic/ozad067.853
View details for PubMedID 37613893
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Resolving Current-Dependent Regimes of Electroplating Mechanisms for Fast Charging Lithium Metal Anodes.
Nano letters
2022
Abstract
Poor fast-charge capabilities limit the usage of rechargeable Li metal anodes. Understanding the connection between charging rate, electroplating mechanism, and Li morphology could enable fast-charging solutions. Here, we develop a combined electroanalytical and nanoscale characterization approach to resolve the current-dependent regimes of Li plating mechanisms and morphology. Measurement of Li+ transport through the solid electrolyte interphase (SEI) shows that low currents induce plating at buried Li||SEI interfaces, but high currents initiate SEI-breakdown and plating at fresh Li||electrolyte interfaces. The latter pathway can induce uniform growth of {110}-faceted Li at extremely high currents, suggesting ion-transport limitations alone are insufficient to predict Li morphology. At battery relevant fast-charging rates, SEI-breakdown above a critical current density produces detrimental morphology and poor cyclability. Thus, prevention of both SEI-breakdown and slow ion-transport in the electrolyte is essential. This mechanistic insight can inform further electrolyte engineering and customization of fast-charging protocols for Li metal batteries.
View details for DOI 10.1021/acs.nanolett.2c02792
View details for PubMedID 36214378
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Remotely controlled near-infrared-triggered photothermal treatment of brain tumours in freely behaving mice using gold nanostars.
Nature nanotechnology
2022
Abstract
Current clinical brain tumour therapy practices are based on tumour resection and post-operative chemotherapy or X-ray radiation. Resection requires technically challenging open-skull surgeries that can lead to major neurological deficits and, in some cases, death. Treatments with X-ray and chemotherapy, on the other hand, cause major side-effects such as damage to surrounding normal brain tissues and other organs. Here we report the development of an integrated nanomedicine-bioelectronics brain-machine interface that enables continuous and on-demand treatment of brain tumours, without open-skull surgery and toxicological side-effects on other organs. Near-infrared surface plasmon characteristics of our gold nanostars enabled the precise treatment of deep brain tumours in freely behaving mice. Moreover, the nanostars' surface coating enabled their selective diffusion in tumour tissues after intratumoral administration, leading to the exclusive heating of tumours for treatment. This versatile remotely controlled and wireless method allows the adjustment of nanoparticles' photothermal strength, as well as power and wavelength of the therapeutic light, to target tumours in different anatomical locations within the brain.
View details for DOI 10.1038/s41565-022-01189-y
View details for PubMedID 35995855
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Strategies for Modulating the Catalytic Activity and Selectivity of Manganese Antimonates for the Oxygen Reduction Reaction
ACS CATALYSIS
2022
View details for DOI 10.1021/acscatal.2c01764
View details for Web of Science ID 000844309700001
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First-Row Transition Metal Antimonates for the Oxygen Reduction Reaction.
ACS nano
2022
Abstract
The development of inexpensive and abundant catalysts with high activity, selectivity, and stability for the oxygen reduction reaction (ORR) is imperative for the widespread implementation of fuel cell devices. Herein, we present a combined theoretical-experimental approach to discover and design first-row transition metal antimonates as excellent electrocatalytic materials for the ORR. Theoretically, we identify first-row transition metal antimonates─MSb2O6, where M = Mn, Fe, Co, and Ni─as nonprecious metal catalysts with good oxygen binding energetics, conductivity, thermodynamic phase stability, and aqueous stability. Among the considered antimonates, MnSb2O6 shows the highest theoretical ORR activity based on the 4e- ORR kinetic volcano. Experimentally, nanoparticulate transition metal antimonate catalysts are found to have a minimum of a 2.5-fold enhancement in intrinsic mass activity (on transition metal mass basis) relative to the corresponding transition metal oxide at 0.7 V vs RHE in 0.1 M KOH. MnSb2O6 is the most active catalyst under these conditions, with a 3.5-fold enhancement on a per Mn mass activity basis and 25-fold enhancement on a surface area basis over its antimony-free counterpart. Electrocatalytic and material stability are demonstrated over a 5 h chronopotentiometry experiment in the stability window identified by theoretical Pourbaix analysis. This study further highlights the stable and electrically conductive antimonate structure as a framework to tune the activity and selectivity of nonprecious metal oxide active sites for ORR catalysis.
View details for DOI 10.1021/acsnano.2c00420
View details for PubMedID 35377139
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Characterization of a Dynamic Y2Ir2O7 Catalyst during the Oxygen Evolution Reaction in Acid
JOURNAL OF PHYSICAL CHEMISTRY C
2022
View details for DOI 10.1021/acs.jpcc.1c07760
View details for Web of Science ID 000746684300001
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An approach for optimizing gold nanoparticles for possible medical applications, using correlative electron energy loss and Raman spectroscopies on electron beam lithographically fabricated arrays
JOURNAL OF MATERIALS RESEARCH
2021
View details for DOI 10.1557/s43578-021-00320-4
View details for Web of Science ID 000702303400001
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Understanding Degradation Mechanisms in SrIrO3 Oxygen Evolution Electrocatalysts: Chemical and Structural Microscopy at the Nanoscale
ADVANCED FUNCTIONAL MATERIALS
2021
View details for DOI 10.1002/adfm.202101542
View details for Web of Science ID 000662722100001
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Persistent and partially mobile oxygen vacancies in Li-rich layered oxides
NATURE ENERGY
2021
View details for DOI 10.1038/s41560-021-00832-7
View details for Web of Science ID 000661400300001
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Epitaxial Stabilization and Oxygen Evolution Reaction Activity of Metastable Columbite Iridium Oxide
ACS APPLIED ENERGY MATERIALS
2021; 4 (4): 3074-3082
View details for DOI 10.1021/acsaem.0c02788
View details for Web of Science ID 000644737800012
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Isolating the Electrocatalytic Activity of a Confined NiFe Motif within Zirconium Phosphate
ADVANCED ENERGY MATERIALS
2021
View details for DOI 10.1002/aenm.202003545
View details for Web of Science ID 000639983100001
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Exploring valence states of abnormal mineral deposits in biological tissues using correlative microscopy and spectroscopy techniques: A case study on ferritin and iron deposits from Alzheimer's disease patients.
Ultramicroscopy
2021: 113254
Abstract
Abnormal accumulation of inorganic trace elements in a human brain, such as iron, zinc and aluminum, oftentimes manifested as deposits and accompanied by a chemical valence change, is pathologically relevant to various neurodegenerative diseases. In particular, Fe2+ has been hypothesized to produce free radicals that induce oxidative damage and eventually cause Alzheimer's disease (AD). However, traditional biomedical techniques, e.g. histology staining, are limited in studying the chemical composition and valence states of these inorganic deposits. We apply commonly used physical (phys-) science methods such as X-ray energy dispersive spectroscopy (EDS), focused-ion beam (FIB) and electron energy loss spectroscopy (EELS) in transmission electron microscopy in conjunction with magnetic resonance imaging (MRI), histology and optical microscopy (OM) to study the valence states of iron deposits in AD patients. Ferrous ions are found in all deposits in brain tissues from three AD patients, constituting 0.22-0.50 of the whole iron content in each specimen. Such phys-techniques are rarely used in medical science and have great potential to provide unique insight into biomedical problems.
View details for DOI 10.1016/j.ultramic.2021.113254
View details for PubMedID 33781589
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Mitochondria-Rich Extracellular Vesicles Rescue Patient-Specific Cardiomyocytes From Doxorubicin Injury: Insights Into the SENECA Trial.
JACC. CardioOncology
2021; 3 (3): 428-440
Abstract
Anthracycline-induced cardiomyopathy (AIC) is a significant source of morbidity and mortality in cancer survivors. The role of mesenchymal stem cells (MSCs) in treating AIC was evaluated in the SENECA trial, a Phase 1 National Heart, Lung, and Blood Institute-sponsored study, but the mechanisms underpinning efficacy in human tissue need clarification.The purpose of this study was to perform an in vitro clinical trial evaluating the efficacy and putative mechanisms of SENECA trial-specific MSCs in treating doxorubicin (DOX) injury, using patient-specific induced pluripotent stem cell-derived cardiomyocytes (iCMs) generated from SENECA patients.Patient-specific iCMs were injured with 1 μmol/L DOX for 24 hours, treated with extracellular vesicles (EVs) from MSCs by either coculture or direct incubation and then assessed for viability and markers of improved cellular physiology. MSC-derived EVs were separated into large extracellular vesicles (L-EVs) (>200 nm) and small EVs (<220nm) using a novel filtration system.iCMs cocultured with MSCs in a transwell system demonstrated improved iCM viability and attenuated apoptosis. L-EVs but not small EVs recapitulated this therapeutic effect. L-EVs were found to be enriched in mitochondria, which were shown to be taken up by iCMs. iCMs treated with L-EVs demonstrated improved contractility, reactive oxygen species production, ATP production, and mitochondrial biogenesis. Inhibiting L-EV mitochondrial function with 1-methyl-4-phenylpyridinium attenuated efficacy.L-EV-mediated mitochondrial transfer mitigates DOX injury in patient-specific iCMs. Although SENECA was not designed to test MSC efficacy, consistent tendencies toward a positive effect were observed across endpoints. Our results suggest a mechanism by which MSCs may improve cardiovascular performance in AIC independent of regeneration, which could inform future trial design evaluating the therapeutic potential of MSCs.
View details for DOI 10.1016/j.jaccao.2021.05.006
View details for PubMedID 34604804
View details for PubMedCentralID PMC8463733
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Identifying and Tuning the In Situ Oxygen-Rich Surface of Molybdenum Nitride Electrocatalysts for Oxygen Reduction
ACS APPLIED ENERGY MATERIALS
2020; 3 (12): 12433–46
View details for DOI 10.1021/acsaem.0c02423
View details for Web of Science ID 000618839200099
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Correlative Microscopy to Localize and Characterize Iron Deposition in Alzheimer's Disease.
Journal of Alzheimer's disease reports
2020; 4 (1): 525–36
Abstract
Background: Recent evidence suggests that the accumulation of iron, specifically ferrous Fe2+, may play a role in the development and progression of neurodegeneration in Alzheimer's disease (AD) through the production of oxidative stress.Objective: To localize and characterize iron deposition and oxidation state in AD, we analyzed human hippocampal autopsy samples from four subjects with advanced AD that have been previously characterized with correlative MRI-histology.Methods: We perform scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and electron energy loss spectroscopy (EELS) in the higher resolution transmission electron microscope on the surface and cross-sections of specific iron-rich regions of interest.Results: Specific previously analyzed regions were visualized using SEM and confirmed to be iron-rich deposits using EDS. Subsequent analysis using focused ion beam cross-sectioning and SEM characterized the iron deposition throughout the 3-D volumes, confirming the presence of iron throughout the deposits, and in two out of four specimens demonstrating colocalization with zinc. Analysis of traditional histology slides showed the analyzed deposits overlapped both with amyloid and tau deposition. Following higher resolution analysis of a single iron deposit using scanning transmission electron microscope (STEM), we demonstrated the potential of monochromated STEM-EELS to discern the relative oxidation state of iron within a deposit.Conclusion: These findings suggest that iron is present in the AD hippocampus and can be visualized and characterized using combined MRI and EM techniques. An altered relative oxidation state may suggest a direct link between iron and oxidative stress in AD. These methods thus could potentially measure an altered relative oxidation state that could suggest a direct link between iron and oxidative stress in AD. Furthermore, we have demonstrated the ability to analyze metal deposition alongside commonly used histological markers of AD pathology, paving the way for future insights into the molecular interactions between Abeta, tau, iron, and other putative metals, such as zinc.
View details for DOI 10.3233/ADR-200234
View details for PubMedID 33532700
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COMBINING THE GLIOBLASTOMA CELL MEMBRANE-PERMEABILIZING EFFECT OF TUMOR TREATING FIELDS (TTFIELDS) WITH WITHAFERIN A (AND OTHER) CHEMOTHERAPY
OXFORD UNIV PRESS INC. 2020: 30
View details for Web of Science ID 000590061300127
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Acidic Oxygen Evolution Reaction Activity-Stability Relationships in Ru-Based Pyrochlores
ACS CATALYSIS
2020; 10 (20): 12182–96
View details for DOI 10.1021/acscatal.0c02252
View details for Web of Science ID 000614389200044
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Atomic Resolution Observation of the Oxidation of Niobium Oxide Nanowires: Implications for Renewable Energy Applications
ACS APPLIED NANO MATERIALS
2020; 3 (9): 9285–92
View details for DOI 10.1021/acsanm.0c01952
View details for Web of Science ID 000575846000077
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Enhancing the nanoplasmonic signal by a nanoparticle sandwiching strategy to detect viruses
APPLIED MATERIALS TODAY
2020; 20
View details for DOI 10.1016/j.apmt.2020.100709
View details for Web of Science ID 000598351900006
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Nanosized Zirconium Porphyrinic Metal-Organic Frameworks that Catalyze the Oxygen Reduction Reaction in Acid
SMALL METHODS
2020
View details for DOI 10.1002/smtd.202000085
View details for Web of Science ID 000557369400001
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Effect of Adventitious Carbon on Pit Formation of Monolayer MoS2.
Advanced materials (Deerfield Beach, Fla.)
2020: e2003020
Abstract
Forming pits on molybdenum disulfide (MoS2 ) monolayers is desirable for (opto)electrical, catalytic, and biological applications. Thermal oxidation is a potentially scalable method to generate pits on monolayer MoS2 , and pits are assumed to preferentially form around undercoordinated sites, such as sulfur vacancies. However, studies on thermal oxidation of MoS2 monolayers have not considered the effect of adventitious carbon (C) that is ubiquitous and interacts with oxygen at elevated temperatures. Herein, the effect of adventitious C on the pit formation on MoS2 monolayers during thermal oxidation is studied. The in situ environmental transmission electron microscopy measurements herein show that pit formation is preferentially initiated at the interface between adventitious C nanoparticles and MoS2 , rather than only sulfur vacancies. Density functional theory (DFT) calculations reveal that the C/MoS2 interface favors the sequential adsorption of oxygen atoms with facile kinetics. These results illustrate the important role of adventitious C on pit formation on monolayer MoS2 .
View details for DOI 10.1002/adma.202003020
View details for PubMedID 32743836
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Combining the glioblastoma cell membrane-permeabilizing effect of tumor treating fields with chemotherapy
AMER ASSOC CANCER RESEARCH. 2020
View details for DOI 10.1158/1538-7445.AM2020-6258
View details for Web of Science ID 000590059307155
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Nitride or Oxynitride? Elucidating the Composition-Activity Relationships in Molybdenum Nitride Electrocatalysts for the Oxygen Reduction Reaction
CHEMISTRY OF MATERIALS
2020; 32 (7): 2946–60
View details for DOI 10.1021/acs.chemmater.9b05212
View details for Web of Science ID 000526394000025
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Pro-efferocytic nanoparticles are specifically taken up by lesional macrophages and prevent atherosclerosis.
Nature nanotechnology
2020
Abstract
Atherosclerosis is the process that underlies heart attack and stroke. A characteristic feature of the atherosclerotic plaque is the accumulation of apoptotic cells in the necrotic core. Prophagocytic antibody-based therapies are currently being explored to stimulate the phagocytic clearance of apoptotic cells; however, these therapies can cause off-target clearance of healthy tissues, which leads to toxicities such as anaemia. Here we developed a macrophage-specific nanotherapy based on single-walled carbon nanotubes loaded with a chemical inhibitor of the antiphagocytic CD47-SIRPα signalling axis. We demonstrate that these single-walled carbon nanotubes accumulate within the atherosclerotic plaque, reactivate lesional phagocytosis and reduce the plaque burden in atheroprone apolipoprotein-E-deficient mice without compromising safety, and thereby overcome a key translational barrier for this class of drugs. Single-cell RNA sequencing analysis reveals that prophagocytic single-walled carbon nanotubes decrease the expression of inflammatory genes linked to cytokine and chemokine pathways in lesional macrophages, which demonstrates the potential of 'Trojan horse' nanoparticles to prevent atherosclerotic cardiovascular disease.
View details for DOI 10.1038/s41565-019-0619-3
View details for PubMedID 31988506
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Comparative electron and photon excitation of localized surface plasmon resonance in lithographic gold arrays for enhanced Raman scattering.
Nanoscale
2020
Abstract
The ability to tune the localized surface plasmon resonance (LSPR) of nanostructures is desirable for surface enhanced Raman spectroscopy (SERS), plasmon-assisted chemistry and other nanophotonic applications. Although historically the LSPR is mainly studied by optical techniques, with the recent advancement in electron monochromators and correctors, it has attracted considerable attention in transmission electron microscopy (TEM). Here, we use electron energy loss spectroscopy (EELS) in a scanning TEM to study individual gold nanodiscs and bowties in lithographic arrays with variable LSPRs by adjusting the size, interspacing, shape and dielectric environment during the nanofabrication process. We observe the strongest Raman signal enhancement when the LSPR frequency is close to the incident laser frequency in Raman spectroscopy. A simplified harmonic oscillator model is used to estimate SERS enhancement factor (EF) from EELS, bridging the connection between electron and photon excitation of plasmonic arrays. This work demonstrates that STEM-EELS shows promise for revealing the contributions of specific LSPR modes to SERS EF. Our results provide guidelines to fine-tune nanoparticle parameters to deliver the maximum signal enhancement in biosensing applications, such as early cancer detection.
View details for DOI 10.1039/d0nr04081a
View details for PubMedID 33232431
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TUMOR TREATING FIELDS LEADS TO CHANGES IN MEMBRANE PERMEABILITY AND INCREASED PENETRATION BY ANTI-GLIOMA DRUGS
OXFORD UNIV PRESS INC. 2019: 93
View details for Web of Science ID 000509478702048
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Editorial for the Special Issue "Characterization of Nanomaterials: Selected Papers from 6th Dresden Nanoanalysis Symposium".
Nanomaterials (Basel, Switzerland)
2019; 9 (11)
Abstract
More than ever before, materials-driven product innovations in industry and shorter time-to-market introductions for new products require high advancement rates and a tight coupling between research, development and manufacturing [...].
View details for DOI 10.3390/nano9111527
View details for PubMedID 31717827
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Cryo-EM Structures of Atomic Surfaces and Host-Guest Chemistry in Metal-Organic Frameworks
MATTER
2019; 1 (2): 428–38
View details for DOI 10.1016/j.matt.2019.06.001
View details for Web of Science ID 000519688200015
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Cryo-EM structures of atomic surfaces and host-guest chemistry in metal-organic frameworks.
Matter
2019; 1 (2): 428-438
Abstract
Host-guest interactions govern the chemistry of a broad range of functional materials, but direct imaging using conventional transmission electron microscopy (TEM) has not been possible. This problem is exacerbated in metal-organic framework (MOF) materials, which are easily damaged by the electron beam. Here, we use cryogenic-electron microscopy (cryo-EM) to stabilize the host-guest structure and resolve the atomic surface of zeolitic imidazolate framework (ZIF-8) and its interaction with guest CO2 molecules. We image step-edge sites on the ZIF-8 surface that provides insight to its growth behavior. Furthermore, we observe two distinct binding sites for CO2 within the ZIF-8 pore, which are predicted by density functional theory (DFT) to be energetically favorable. This CO2 insertion induces an apparent ~3% lattice expansion along the <002> and <011> directions of the ZIF-8 unit cell. The ability to stabilize and preserve host-guest chemistry opens a rich materials space for scientific exploration and discovery using cryo-EM.
View details for DOI 10.1016/j.matt.2019.06.001
View details for PubMedID 34104881
View details for PubMedCentralID PMC8184120
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Magnetization switching using topological surface states.
Science advances
2019; 5 (8): eaaw3415
Abstract
Topological surface states (TSSs) in a topological insulator are expected to be able to produce a spin-orbit torque that can switch a neighboring ferromagnet. This effect may be absent if the ferromagnet is conductive because it can completely suppress the TSSs, but it should be present if the ferromagnet is insulating. This study reports TSS-induced switching in a bilayer consisting of a topological insulator Bi2Se3 and an insulating ferromagnet BaFe12O19. A charge current in Bi2Se3 can switch the magnetization in BaFe12O19 up and down. When the magnetization is switched by a field, a current in Bi2Se3 can reduce the switching field by ~4000 Oe. The switching efficiency at 3 K is 300 times higher than at room temperature; it is ~30 times higher than in Pt/BaFe12O19. These strong effects originate from the presence of more pronounced TSSs at low temperatures due to enhanced surface conductivity and reduced bulk conductivity.
View details for DOI 10.1126/sciadv.aaw3415
View details for PubMedID 31497642
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Precious Metal-Free Nickel Nitride Catalyst for the Oxygen Reduction Reaction.
ACS applied materials & interfaces
2019
Abstract
With promising activity and stability for the oxygen reduction reaction (ORR), transition metal nitrides are an interesting class of non-platinum group catalysts for polymer electrolyte membrane fuel cells. Here, we report an active thin-film nickel nitride catalyst synthesized through a reactive sputtering method. In rotating disk electrode testing in a 0.1 M HClO4 electrolyte, the crystalline nickel nitride film achieved high activity and selectivity to four-electron ORR. It also exhibited good stability during 10 and 40 h chronoamperometry measurements in acid and alkaline electrolyte, respectively. A combined experiment-theory approach, with detailed ex situ materials characterization and density functional theory calculations, provides insight into the structure of the catalyst and its surface during catalysis. Design strategies for activity and stability improvement through alloying and nanostructuring are discussed.
View details for DOI 10.1021/acsami.9b07116
View details for PubMedID 31310093
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Intranasal delivery of targeted polyfunctional gold-iron oxide nanoparticles loaded with therapeutic microRNAs for combined theranostic multimodality imaging and presensitization of glioblastoma to temozolomide.
Biomaterials
2019; 218: 119342
Abstract
The prognosis for glioblastoma (GBM) remains depressingly low. The biological barriers of the brain present a major challenge to achieving adequate drug concentrations for GBM therapy. To address this, we explore the potential of the nose-to-brain direct transport pathway to bypass the blood-brain barrier, and to enable targeted delivery of theranostic polyfunctional gold-iron oxide nanoparticles (polyGIONs) surface loaded with therapeutic miRNAs (miR-100 and antimiR-21) to GBMs in mice. These nanoformulations would thus allow presensitization of GBM cells to the systemically delivered chemotherapy drug temozolomide (TMZ), as well as in vivo multimodality molecular and anatomic imaging of nanoparticle delivery, trafficking, and treatment effects. First, we synthesized GIONs coated with beta-cyclodextrin-chitosan (CD-CS) hybrid polymer, and co-loaded with miR-100 and antimiR-21. Then we decorated their surface with PEG-T7 peptide using CD-adamantane host-guest chemistry. The resultant polyGIONs showed efficient miRNA loading with enhanced serum stability. We characterized them for particle size, PDI, polymer functionalization, charge and release using dynamic light scattering analysis, TEM and qRT-PCR. For in vivo intranasal delivery, we used U87-MG GBM cell-derived orthotopic xenograft models in mice. Intranasal delivery resulted in efficient accumulation of Cy5-miRNAs in mice treated with T7-targeted polyGIONs, as demonstrated by in vivo optical fluorescence and MR imaging. We measured the therapeutic response of these FLUC-EGFP labelled U87-MG GBMs using bioluminescence imaging. Overall, there was a significant increase in survival of mice co-treated with T7-polyGIONs loaded with miR-100/antimiR-21 plus systemic TMZ, compared to the untreated control group, or the animals receiving non-targeted polyGIONs-miR-100/antimiR-21, or TMZ alone. Once translated clinically, this novel theranostic nanoformulation and its associated intranasal delivery strategy will have a strong potential to potentiate the effects of TMZ treatment in GBM patients.
View details for DOI 10.1016/j.biomaterials.2019.119342
View details for PubMedID 31326657
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Tumor treating fields increases membrane permeability in glioblastoma cells
AMER ASSOC CANCER RESEARCH. 2019
View details for DOI 10.1158/1538-7445.AM2019-250
View details for Web of Science ID 000488129901424
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Nanomedicine for Spontaneous Brain Tumors: A Companion Clinical Trial.
ACS nano
2019
Abstract
Nanoparticles' enhanced permeation and retention (EPR) variations due to tumor heterogeneity in naturally occurring brain tumors are commonly neglected in preclinical nanomedicine studies. Recent pathological studies have shown striking similarities between brain tumors in humans and dogs, indicating that canine brain tumors may be a valuable model to evaluate nanoparticles' EPR in this context. We recruited canine clinical cases with spontaneous brain tumors to investigate nanoparticles' EPR in different brain tumor pathologies using surface-enhanced Raman spectroscopy (SERS). We used gold nanoparticles due to their surface plasmon effect that enables their sensitive and microscopic resolution detection using the SERS technique. Raman microscopy of the resected tumors showed heterogeneous EPR of nanoparticles into oligodendrogliomas and meningiomas of different grades, without any detectable traces in necrotic parts of the tumors or normal brain. Raman observations were confirmed by scanning electron microscopy (SEM) and X-ray elemental analyses, which enabled localization of individual nanoparticles embedded in tumor tissues. Our results demonstrate nanoparticles' EPR and its variations in clinically relevant, spontaneous brain tumors. Such heterogeneities should be considered alongside routine preoperative imaging and histopathological analyses in order to accelerate clinical management of brain tumors using nanomedicine approaches.
View details for PubMedID 30714717
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Optimizing Nanostructure Size to Yield High Raman Signal Enhancement by Electron Energy Loss Spectroscopy.
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada
2019; 25 (Suppl 2): 610–11
View details for DOI 10.1017/S1431927619003787
View details for PubMedID 31511763
View details for PubMedCentralID PMC6738940
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Visualizing Facet-Dependent Hydrogenation Dynamics in Individual Palladium Nanoparticles.
Nano letters
2018
Abstract
Surface faceting in nanoparticles can profoundly impact the rate and selectivity of chemical transformations. However, the precise role of surface termination can be challenging to elucidate because many measurements are performed on ensembles of particles and do not have sufficient spatial resolution to observe reactions at the single and subparticle level. Here, we investigate solute intercalation in individual palladium hydride nanoparticles with distinct surface terminations. Using a combination of diffraction, electron energy loss spectroscopy, and dark-field contrast in an environmental transmission electron microscope (TEM), we compare the thermodynamics and directly visualize the kinetics of 40-70 nm {100}-terminated cubes and {111}-terminated octahedra with approximately 2 nm spatial resolution. Despite their distinct surface terminations, both particle morphologies nucleate the new phase at the tips of the particle. However, whereas the hydrogenated phase-front must rotate from [111] to [100] to propagate in cubes, the phase-front can propagate along the [100], [110], and [111] directions in octahedra. Once the phase-front is established, the interface propagates linearly with time and is rate-limited by surface-to-subsurface diffusion and/or the atomic rearrangements needed to accommodate lattice strain. Following nucleation, both particle morphologies take approximately the same time to reach equilibrium, hydrogenating at similar pressures and without equilibrium phase coexistence. Our results highlight the importance of low-coordination number sites and strain, more so than surface faceting, in governing solute-driven reactions.
View details for PubMedID 30148640
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Synthesis, characterization and light-induced spatial charge separation in Janus graphene oxide
AMER CHEMICAL SOC. 2018
View details for Web of Science ID 000447600003844
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In-situ observation of plasmon-driven hydrogenation reactions within Au@Pd coreshell nanoparticles
AMER CHEMICAL SOC. 2018
View details for Web of Science ID 000447600004349
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Rapid flame doping of Co to WS2 for efficient hydrogen evolution
ENERGY & ENVIRONMENTAL SCIENCE
2018; 11 (8): 2270–77
View details for DOI 10.1039/c8ee01111g
View details for Web of Science ID 000442262900035
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Contributions to High Resolution and In Situ Electron Microscopy.
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada
2018; 24 (Suppl 1): 10–11
View details for DOI 10.1017/S1431927618000545
View details for PubMedID 30498393
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Designing Boron Nitride Islands in Carbon Materials for Efficient Electrochemical Synthesis of Hydrogen Peroxide.
Journal of the American Chemical Society
2018; 140 (25): 7851–59
Abstract
Heteroatom-doped carbons have drawn increasing research interest as catalysts for various electrochemical reactions due to their unique electronic and surface structures. In particular, co-doping of carbon with boron and nitrogen has been shown to provide significant catalytic activity for oxygen reduction reaction (ORR). However, limited experimental work has been done to systematically study these materials, and much remains to be understood about the nature of the active site(s), particularly with regards to the factors underlying the activity enhancements of these boron-carbon-nitrogen (BCN) materials. Herein, we prepare several BCN materials experimentally with a facile and controlled synthesis method, and systematically study their electrochemical performance. We demonstrate the existence of h-BN domains embedded in the graphitic structures of these materials using X-ray spectroscopy. These synthesized structures yield higher activity and selectivity toward the 2e- ORR to H2O2 than structures with individual B or N doping. We further employ density functional theory calculations to understand the role of a variety of h-BN domains within the carbon lattice for the ORR and find that the interface between h-BN domains and graphene exhibits unique catalytic behavior that can preferentially drive the production of H2O2. To the best of our knowledge, this is the first example of h-BN domains in carbon identified as a novel system for the electrochemical production of H2O2.
View details for PubMedID 29874062
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Atomic and Molecular Layer Deposition of Hybrid Mo-Thiolate Thin Films with Enhanced Catalytic Activity
ADVANCED FUNCTIONAL MATERIALS
2018; 28 (26)
View details for DOI 10.1002/adfm.201800852
View details for Web of Science ID 000436104800016
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Synthesis, Characterization, and Light-Induced Spatial Charge Separation in Janus Graphene Oxide
CHEMISTRY OF MATERIALS
2018; 30 (6): 2084–92
View details for DOI 10.1021/acs.chemmater.8b00087
View details for Web of Science ID 000428712200031
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Deformable Organic Nanowire Field-Effect Transistors
ADVANCED MATERIALS
2018; 30 (7)
View details for DOI 10.1002/adma.201704401
View details for Web of Science ID 000424891900009
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Deformable Organic Nanowire Field-Effect Transistors.
Advanced materials (Deerfield Beach, Fla.)
2018; 30 (7)
Abstract
Deformable electronic devices that are impervious to mechanical influence when mounted on surfaces of dynamically changing soft matters have great potential for next-generation implantable bioelectronic devices. Here, deformable field-effect transistors (FETs) composed of single organic nanowires (NWs) as the semiconductor are presented. The NWs are composed of fused thiophene diketopyrrolopyrrole based polymer semiconductor and high-molecular-weight polyethylene oxide as both the molecular binder and deformability enhancer. The obtained transistors show high field-effect mobility >8 cm2 V-1 s-1 with poly(vinylidenefluoride-co-trifluoroethylene) polymer dielectric and can easily be deformed by applied strains (both 100% tensile and compressive strains). The electrical reliability and mechanical durability of the NWs can be significantly enhanced by forming serpentine-like structures of the NWs. Remarkably, the fully deformable NW FETs withstand 3D volume changes (>1700% and reverting back to original state) of a rubber balloon with constant current output, on the surface of which it is attached. The deformable transistors can robustly operate without noticeable degradation on a mechanically dynamic soft matter surface, e.g., a pulsating balloon (pulse rate: 40 min-1 (0.67 Hz) and 40% volume expansion) that mimics a beating heart, which underscores its potential for future biomedical applications.
View details for DOI 10.1002/adma.201704401
View details for PubMedID 29315845
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Anti-Hermitian photodetector facilitating efficient subwavelength photon sorting
NATURE COMMUNICATIONS
2018; 9: 316
Abstract
The ability to split an incident light beam into separate wavelength bands is central to a diverse set of optical applications, including imaging, biosensing, communication, photocatalysis, and photovoltaics. Entirely new opportunities are currently emerging with the recently demonstrated possibility to spectrally split light at a subwavelength scale with optical antennas. Unfortunately, such small structures offer limited spectral control and are hard to exploit in optoelectronic devices. Here, we overcome both challenges and demonstrate how within a single-layer metafilm one can laterally sort photons of different wavelengths below the free-space diffraction limit and extract a useful photocurrent. This chipscale demonstration of anti-Hermitian coupling between resonant photodetector elements also facilitates near-unity photon-sorting efficiencies, near-unity absorption, and a narrow spectral response (∼ 30 nm) for the different wavelength channels. This work opens up entirely new design paradigms for image sensors and energy harvesting systems in which the active elements both sort and detect photons.
View details for PubMedID 29358626
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In-situ visualization of solute-driven phase coexistence within individual nanorods.
Nature communications
2018; 9 (1): 1775
Abstract
Nanorods are promising components of energy and information storage devices that rely on solute-driven phase transformations, due to their large surface-to-volume ratio and ability to accommodate strain. Here we investigate the hydrogen-induced phase transition in individual penta-twinned palladium nanorods of varying aspect ratios with ~3 nm spatial resolution to understand the correlation between nanorod structure and thermodynamics. We find that the hydrogenated phase preferentially nucleates at the rod tips, progressing along the length of the nanorods with increasing hydrogen pressure. While nucleation pressure is nearly constant for all lengths, the number of phase boundaries is length-dependent, with stable phase coexistence always occurring for rods longer than 55 nm. Moreover, such coexistence occurs within individual crystallites of the nanorods and is accompanied by defect formation, as supported by in situ electron microscopy and elastic energy calculations. These results highlight the effect of particle shape and dimension on thermodynamics, informing nanorod design for improved device cyclability.
View details for PubMedID 29720644
View details for PubMedCentralID PMC5932065
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Correlative Magnetic Imaging of Heat-Assisted Magnetic Recording Media in Cross Section Using Lorentz TEM and MFM
IEEE TRANSACTIONS ON MAGNETICS
2018; 54 (1)
View details for DOI 10.1109/TMAG.2017.2753170
View details for Web of Science ID 000418756900017
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Tumor treating fields increases membrane permeability in glioblastoma cells.
Cell death discovery
2018; 4: 113
Abstract
Glioblastoma is the most common yet most lethal of primary brain cancers with a one-year post-diagnosis survival rate of 65% and a five-year survival rate of barely 5%. Recently the U.S. Food and Drug Administration approved a novel fourth approach (in addition to surgery, radiation therapy, and chemotherapy) to treating glioblastoma; namely, tumor treating fields (TTFields). TTFields involves the delivery of alternating electric fields to the tumor but its mechanisms of action are not fully understood. Current theories involve TTFields disrupting mitosis due to interference with proper mitotic spindle assembly. We show that TTFields also alters cellular membrane structure thus rendering it more permeant to chemotherapeutics. Increased membrane permeability through the imposition of TTFields was shown by several approaches. For example, increased permeability was indicated through increased bioluminescence with TTFields exposure or with the increased binding and ingress of membrane-associating reagents such as Dextran-FITC or ethidium D or with the demonstration by scanning electron microscopy of augmented number and sizes of holes on the cellular membrane. Further investigations showed that increases in bioluminescence and membrane hole production with TTFields exposure disappeared by 24 h after cessation of alternating electric fields thus demonstrating that this phenomenom is reversible. Preliminary investigations showed that TTFields did not induce membrane holes in normal human fibroblasts thus suggesting that the phenomenom was specific to cancer cells. With TTFields, we present evidence showing augmented membrane accessibility by compounds such as 5-aminolevulinic acid, a reagent used intraoperatively to delineate tumor from normal tissue in glioblastoma patients. In addition, this mechanism helps to explain previous reports of additive and synergistic effects between TTFields and other chemotherapies. These findings have implications for the design of combination therapies in glioblastoma and other cancers and may significantly alter standard of care strategies for these diseases.
View details for PubMedID 30534421
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Tumor Treating Fields Increases Membrane Permeability in Glioblastoma Cells
Cell Death Discovery
2018; 4
View details for DOI 10.1038/s41420-018-0130-x
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Tumor Cell-Derived Extracellular Vesicle-Coated Nanocarriers: An Efficient Theranostic Platform for the Cancer-Specific Delivery of Anti-miR-21 and Imaging Agents.
ACS nano
2018
Abstract
MicroRNAs are critical regulators of cancer initiation, progression, and dissemination. Extensive evidence suggests that the inhibition of over-expressed oncogenic miRNA function can be a robust strategy for anticancer therapy. However, in vivo targeted delivery of miRNA therapeutics to various types of cancers remains a major challenge. Inspired by their natural synthesis and cargo delivery capabilities, researchers have exploited tumor cell-derived extracellular vesicles (TEVs) for the cancer-targeted delivery of therapeutics and theranostics. Here, we investigate a TEV-based nanoplatform for multimodal miRNA delivery and phototherapy treatments as well as the magnetic resonance imaging of cancer. We demonstrated loading of anti-miR-21 that blocks the function of endogenous oncogenic miR-21 over-expressed in cancer cells into and subsequent delivery by TEVs derived from 4T1 cells. We also produced Cy5-anti-miR-21-loaded TEVs from two other cancer cell lines (HepG2 and SKBR3) and confirmed their robust homologous and heterologous transfection efficiency and intracellular Cy5-anti-miR-21 delivery. Additionally, TEV-mediated anti-miR-21 delivery attenuated doxorubicin (DOX) resistance in breast cancer cells with a 3-fold higher cell kill efficiency than in cells treated with DOX alone. We then investigated TEVs as a biomimetic source for the functionalization of gold-iron oxide nanoparticles (GIONs) and demonstrated nanotheranostic properties of TEV-GIONs in vitro. TEV-GIONs demonstrated excellent T2 contrast in in vitro magnetic resonance (MR) imaging and resulted in efficient photothermal effect in 4T1 cells. We also evaluated the biodistribution and theranostic property of anti-miR-21 loaded TEV-GIONs in vivo by labeling with indocyanine green near-infrared dye. We further validated the tumor specific accumulation of TEV-GIONs using MR imaging. Our findings demonstrate that the distribution pattern of the TEV-anti-miR-21-GIONs correlated well with the tumor-targeting capability as well as the activity and efficacy obtained in response to doxorubicin combination treatments. TEVs and TEV-GIONs are promising nanotheranostics for future applications in cancer molecular imaging and therapy.
View details for PubMedID 30346694
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Defective Carbon-Based Materials for the Electrochemical Synthesis of Hydrogen Peroxide
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
2018; 6 (1): 311–17
View details for DOI 10.1021/acssuschemeng.7b02517
View details for Web of Science ID 000419536800034
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Synthesis and characterization of graphite-encapsulated iron nanoparticles from ball milling-assisted low-pressure chemical vapor deposition
CARBON
2017; 124: 170–79
Abstract
Graphite-encapsulated Fe nanoparticles were synthesized using a combined method of high-energy ball milling and low-pressure chemical vapor deposition (LPCVD). Fe2O3 and graphite powders were milled to increase their surface areas and obtain a more homogeneous distribution. LPCVD was performed at a pressure of ~0.57 Torr in a tube furnace under a CH4/H2 atmosphere at 1050°C for 1 and 3 h. As-synthesized samples were purified in a 2 M HF solution. Characterization was performed using X-ray diffractometry (XRD), scanning and transmission electron microscopy (SEM and TEM) and alternating gradient magnetometry (AGM). XRD revealed the presence of body centered cubic (BCC) and face centered cubic (FCC) Fe phases without residual iron oxides. SEM confirmed the powders were better mixed and smaller after ball milling compared to mortar and pestle milled powders. High resolution TEM showed all nanoparticles had at least four and on average 16 graphitic layers, around an Fe core ranging from 20-300 nm. Magnetic measurements indicated that nanoparticles exhibit soft ferromagnetic behavior with low saturation magnetization (17-21 emu/g) and coercivity (110 Oe). A chemical stability test performed in a 2 M HCl solution showed that graphitic shells did not degrade, nor was there evidence of core dissolution or shell discontinuity.
View details for PubMedID 29434378
View details for PubMedCentralID PMC5807011
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Highly Stable Molybdenum Disulfide Protected Silicon Photocathodes for Photoelectrochemical Water Splitting
ACS APPLIED MATERIALS & INTERFACES
2017; 9 (42): 36792–98
Abstract
Developing materials, interfaces, and devices with improved stability remains one of the key challenges in the field of photoelectrochemical water splitting. As a barrier to corrosion, molybdenum disulfide is a particularly attractive protection layer for photocathodes due to its inherent stability in acid, the low permeability of its basal planes, and the excellent hydrogen evolution reaction (HER) activity the MoS2 edge. Here, we demonstrate a stable silicon photocathode containing a protecting layer consisting of molybdenum disulfide, molybdenum silicide, and silicon oxide which operates continuously for two months. We make comparisons between this system and another molybdenum sulfide-silicon photocathode embodiment, taking both systems to catastrophic failure during photoelectrochemical stability measurements and exploring mechanisms of degradation. X-ray photoelectron spectroscopy and transmission electron microscopy provide key insights into the origins of stability.
View details for PubMedID 29035498
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Intrinsic Chirality Origination in Carbon Nanotubes.
ACS nano
2017; 11 (10): 9941-9949
Abstract
Elucidating the origin of carbon nanotube chirality is key for realizing their untapped potential. Currently, prevalent theories suggest that catalyst structure originates chirality via an epitaxial relationship. Here we studied chirality abundances of carbon nanotubes grown on floating liquid Ga droplets, which excludes the influence of catalyst features, and compared them with abundances grown on solid Ru nanoparticles. Results of growth on liquid droplets bolsters the intrinsic preference of carbon nuclei toward certain chiralities. Specifically, the abundance of the (11,1)/χ = 4.31° tube can reach up to 95% relative to (9,4)/χ = 17.48°, although they have exactly the same diameter, (9.156 Å). However, the comparative abundances for the pair, (19,3)/χ = 7.2° and (17,6)/χ = 14.5°, with bigger diameter, (16.405 Å), fluctuate depending on synthesis temperature. The abundances of the same pairs of tubes grown on floating solid polyhedral Ru nanoparticles show completely different trends. Analysis of abundances in relation to nucleation probability, represented by a product of the Zeldovich factor and the deviation interval of a growing nuclei from equilibrium critical size, explain the findings. We suggest that the chirality in the nanotube in general is a result of interplay between intrinsic preference of carbon cluster and induction by catalyst structure. This finding can help to build the comprehensive theory of nanotube growth and offers a prospect for chirality-preferential synthesis of carbon nanotubes by the exploitation of liquid catalyst droplets.
View details for DOI 10.1021/acsnano.7b03957
View details for PubMedID 28953362
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In Situ Field Emission of Carbon Nanotubes in Oxygen Using Environmental TEM and the Influence of the Imaging Electron Beam.
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada
2017; 23 (Suppl 1): 910-911
View details for DOI 10.1017/S1431927617005219
View details for PubMedID 31649486
View details for PubMedCentralID PMC6812553
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depends non-monotonically on large biaxial strain.
Nature communications
2017; 8: 15360-?
Abstract
Elastic strain is being increasingly employed to enhance the catalytic properties of mixed ion-electron conducting oxides. However, its effect on oxygen storage capacity is not well established. Here, we fabricate ultrathin, coherently strained films of CeO2-δ between 5.6% biaxial compression and 2.1% tension. In situ ambient pressure X-ray photoelectron spectroscopy reveals up to a fourfold enhancement in equilibrium oxygen storage capacity under both compression and tension. This non-monotonic variation with strain departs from the conventional wisdom based on a chemical expansion dominated behaviour. Through depth profiling, film thickness variations and a coupled photoemission-thermodynamic analysis of space-charge effects, we show that the enhanced reducibility is not dominated by interfacial effects. On the basis of ab initio calculations of oxygen vacancy formation incorporating defect interactions and vibrational contributions, we suggest that the non-monotonicity arises from the tetragonal distortion under large biaxial strain. These results may guide the rational engineering of multilayer and core-shell oxide nanomaterials.
View details for DOI 10.1038/ncomms15360
View details for PubMedID 28516915
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Equilibrium oxygen storage capacity of ultrathin CeO2-delta depends non-monotonically on large biaxial strain
NATURE COMMUNICATIONS
2017; 8
View details for DOI 10.1038/ncomms15360
View details for Web of Science ID 000401509500001
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Structure and chemistry of epitaxial ceria thin films on yttria-stabilized zirconia substrates, studied by high resolution electron microscopy.
Ultramicroscopy
2017; 176: 200-211
Abstract
We have applied aberration-corrected transmission electron microscopy (TEM) imaging and electron energy loss spectroscopy (EELS) to study the structure and chemistry of epitaxial ceria thin films, grown by pulsed laser deposition onto (001) yttria-stabilized zirconia (YSZ) substrates. There are few observable defects apart from the expected mismatch interfacial dislocations and so the films would be expected to have good potential for applications. Under high electron beam dose rate (above about 6000 e(-)/Å(2)s) domains of an ordered structure appear and these are interpreted as being created by oxygen vacancy ordering. The ordered structure does not appear at lower lose rates (ca. 2600 e(-)/Å(2)s) and can be removed by imaging under 1 mbar oxygen gas in an environmental TEM. EELS confirms that there is both oxygen deficiency and the associated increase in Ce(3+) versus Ce(4+) cations in the ordered domains. In situ high resolution TEM recordings show the formation of the ordered domains as well as atomic migration along the ceria thin film (001) surface.
View details for DOI 10.1016/j.ultramic.2017.03.015
View details for PubMedID 28341554
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Magnetic and electric properties of triangular lattice antiferromagnets Ba(3)ATa(2)O(9) (A = Ni and Co)
MATERIALS RESEARCH BULLETIN
2017; 88: 308-314
View details for DOI 10.1016/j.materresbull.2016.12.039
View details for Web of Science ID 000393635500041
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Canted magnetic ground state of quarterdoped manganites R0.75Ca0.25MnO3 (R = Y, Tb, Dy, Ho, and Er)
JOURNAL OF PHYSICS-CONDENSED MATTER
2017; 29 (6)
View details for DOI 10.1088/1361-648X/aa4de1
View details for Web of Science ID 000391713600002
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Observing Plasmon Damping Due to Adhesion Layers in Gold Nanostructures Using Electron Energy Loss Spectroscopy.
ACS photonics
2017; 4 (2): 268-274
Abstract
Gold plasmonic nanostructures with several different adhesion layers have been studied with monochromated electron energy loss spectroscopy in the scanning transmission electron microscope (STEM-EELS) and with surface enhanced Raman spectroscopy (SERS). Compared to samples with no adhesion layer, those with 2nm of Cr or Ti show broadened, lower intensity plasmon peaks as measured with EELS. This broadening is observed in both optically active ("bright") and inactive ("dark") plasmon modes. When the former are probed with SERS, the signal enhancement factor is lower for samples with Cr or Ti, another indication of reduced plasmon resonance. This work illustrates the capability of STEM-EELS to provide direct near-field measurement of changes in plasmon excitation probability with nano-scale spatial resolution. Additionally, it demonstrates that applications which require high SERS enhancement, such as biomarker detection and cancer diagnostics, can be improved by avoiding the use of a metallic adhesion layer.
View details for DOI 10.1021/acsphotonics.6b00525
View details for PubMedID 28944259
View details for PubMedCentralID PMC5604478
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Observing Plasmon Damping Due to Adhesion Layers in Gold Nanostructures Using Electron Energy Loss Spectroscopy
ACS PHOTONICS
2017; 4 (2): 268-274
Abstract
Gold plasmonic nanostructures with several different adhesion layers have been studied with monochromated electron energy loss spectroscopy in the scanning transmission electron microscope (STEM-EELS) and with surface enhanced Raman spectroscopy (SERS). Compared to samples with no adhesion layer, those with 2nm of Cr or Ti show broadened, lower intensity plasmon peaks as measured with EELS. This broadening is observed in both optically active ("bright") and inactive ("dark") plasmon modes. When the former are probed with SERS, the signal enhancement factor is lower for samples with Cr or Ti, another indication of reduced plasmon resonance. This work illustrates the capability of STEM-EELS to provide direct near-field measurement of changes in plasmon excitation probability with nano-scale spatial resolution. Additionally, it demonstrates that applications which require high SERS enhancement, such as biomarker detection and cancer diagnostics, can be improved by avoiding the use of a metallic adhesion layer.
View details for DOI 10.1021/acsphotonics.6b00525
View details for Web of Science ID 000394483500011
View details for PubMedCentralID PMC5604478
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Direct visualization of hydrogen absorption dynamics in individual palladium nanoparticles
NATURE COMMUNICATIONS
2017; 8
View details for DOI 10.1038/ncomms14020
View details for Web of Science ID 000391869800001
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Direct visualization of hydrogen absorption dynamics in individual palladium nanoparticles.
Nature communications
2017; 8: 14020-?
Abstract
Many energy storage materials undergo large volume changes during charging and discharging. The resulting stresses often lead to defect formation in the bulk, but less so in nanosized systems. Here, we capture in real time the mechanism of one such transformation-the hydrogenation of single-crystalline palladium nanocubes from 15 to 80 nm-to better understand the reason for this durability. First, using environmental scanning transmission electron microscopy, we monitor the hydrogen absorption process in real time with 3 nm resolution. Then, using dark-field imaging, we structurally examine the reaction intermediates with 1 nm resolution. The reaction proceeds through nucleation and growth of the new phase in corners of the nanocubes. As the hydrogenated phase propagates across the particles, portions of the lattice misorient by 1.5%, diminishing crystal quality. Once transformed, all the particles explored return to a pristine state. The nanoparticles' ability to remove crystallographic imperfections renders them more durable than their bulk counterparts.
View details for DOI 10.1038/ncomms14020
View details for PubMedID 28091597
View details for PubMedCentralID PMC5241819
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Highly stretchable polymer semiconductor films through the nanoconfinement effect
SCIENCE
2017; 355 (6320): 59-?
Abstract
Soft and conformable wearable electronics require stretchable semiconductors, but existing ones typically sacrifice charge transport mobility to achieve stretchability. We explore a concept based on the nanoconfinement of polymers to substantially improve the stretchability of polymer semiconductors, without affecting charge transport mobility. The increased polymer chain dynamics under nanoconfinement significantly reduces the modulus of the conjugated polymer and largely delays the onset of crack formation under strain. As a result, our fabricated semiconducting film can be stretched up to 100% strain without affecting mobility, retaining values comparable to that of amorphous silicon. The fully stretchable transistors exhibit high biaxial stretchability with minimal change in on current even when poked with a sharp object. We demonstrate a skinlike finger-wearable driver for a light-emitting diode.
View details for DOI 10.1126/science.aah4496
View details for PubMedID 28059762
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Structure and chemistry of epitaxial ceria thin films on yttria-stabilized zirconia substrates, studied by high resolution electron microscopy.
Ultramicroscopy
2017; 175: 25-35
Abstract
We have applied aberration-corrected transmission electron microscopy (TEM) imaging and electron energy loss spectroscopy (EELS) to study the structure and chemistry of epitaxial ceria thin films, grown by pulsed laser deposition onto (001) yttria-stabilized zirconia (YSZ) substrates. There are few observable defects apart from the expected mismatch interfacial dislocations and so the films would be expected to have good potential for applications. Under high electron beam dose rate (above about 6000 e(-)/Å(2)s) domains of an ordered structure appear and these are interpreted as being created by oxygen vacancy ordering. The ordered structure does not appear at lower lose rates (ca. 2600 e(-)/Å(2)s) and can be removed by imaging under 1 mbar oxygen gas in an environmental TEM. EELS confirms that there is both oxygen deficiency and the associated increase in Ce(3+) versus Ce(4+) cations in the ordered domains. In situ high resolution TEM recordings show the formation of the ordered domains as well as atomic migration along the ceria thin film (001) surface.
View details for DOI 10.1016/j.ultramic.2016.12.023
View details for PubMedID 28110261
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The Exosome Total Isolation Chip.
ACS nano
2017
Abstract
Circulating tumor-derived extracellular vesicles (EVs) have emerged as a promising source for identifying cancer biomarkers for early cancer detection. However, the clinical utility of EVs has thus far been limited by the fact that most EV isolation methods are tedious, nonstandardized, and require bulky instrumentation such as ultracentrifugation (UC). Here, we report a size-based EV isolation tool called ExoTIC (exosome total isolation chip), which is simple, easy-to-use, modular, and facilitates high-yield and high-purity EV isolation from biofluids. ExoTIC achieves an EV yield ∼4-1000-fold higher than that with UC, and EV-derived protein and microRNA levels are well-correlated between the two methods. Moreover, we demonstrate that ExoTIC is a modular platform that can sort a heterogeneous population of cancer cell line EVs based on size. Further, we utilize ExoTIC to isolate EVs from cancer patient clinical samples, including plasma, urine, and lavage, demonstrating the device's broad applicability to cancers and other diseases. Finally, the ability of ExoTIC to efficiently isolate EVs from small sample volumes opens up avenues for preclinical studies in small animal tumor models and for point-of-care EV-based clinical testing from fingerprick quantities (10-100 μL) of blood.
View details for DOI 10.1021/acsnano.7b04878
View details for PubMedID 29090896
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Ultratransparent and stretchable graphene electrodes.
Science advances
2017; 3 (9): e1700159
Abstract
Two-dimensional materials, such as graphene, are attractive for both conventional semiconductor applications and nascent applications in flexible electronics. However, the high tensile strength of graphene results in fracturing at low strain, making it challenging to take advantage of its extraordinary electronic properties in stretchable electronics. To enable excellent strain-dependent performance of transparent graphene conductors, we created graphene nanoscrolls in between stacked graphene layers, referred to as multilayer graphene/graphene scrolls (MGGs). Under strain, some scrolls bridged the fragmented domains of graphene to maintain a percolating network that enabled excellent conductivity at high strains. Trilayer MGGs supported on elastomers retained 65% of their original conductance at 100% strain, which is perpendicular to the direction of current flow, whereas trilayer films of graphene without nanoscrolls retained only 25% of their starting conductance. A stretchable all-carbon transistor fabricated using MGGs as electrodes exhibited a transmittance of >90% and retained 60% of its original current output at 120% strain (parallel to the direction of charge transport). These highly stretchable and transparent all-carbon transistors could enable sophisticated stretchable optoelectronics.
View details for PubMedID 28913422
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Assessing and ameliorating the influence of the electron beam on carbon nanotube oxidation in environmental transmission electron microscopy.
Ultramicroscopy
2016
Abstract
In this work, we examine how the imaging electron beam can induce damage in carbon nanotubes (CNTs) at varying oxygen gas pressures and electron dose rates using environmental transmission electron microscopy (ETEM). Our studies show that there is a threshold cumulative electron dose which brings about damage in CNTs in oxygen - through removal of their graphitic walls - which is dependent on O2 pressure, with a 4-5 fold decrease in total electron dose per decade increase at a lower pressure range (10(-6) to 10(-5)mbar) and approximately 1.3 -fold decrease per decade increase at a higher pressure range (10(-3) to 10(0)mbar). However, at a given pressure, damage in CNTs was found to occur even at the lowest dose rate utilized, suggesting the absence of a lower limit for the latter parameter. This study provides guidelines on the cumulative dose required to damage nanotubes in the 10(-7)mbar to 10(0)mbar pressure regimes, and discusses the role of electron dose rate and total electron dose on beam-induced CNT degradation experiments.
View details for DOI 10.1016/j.ultramic.2016.12.009
View details for PubMedID 27979618
View details for PubMedCentralID PMC5392373
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Magnetism and multiferroicity of an isosceles triangular lattice antiferromagnet Sr3NiNb2O9
JOURNAL OF PHYSICS-CONDENSED MATTER
2016; 28 (47)
Abstract
Various experimental measurements were performed to complete the phase diagram of a weakly distorted triangular lattice system, Sr3NiNb2O9 with Ni(2+) , spin-1 magnetic ions. This compound possesses an isosceles triangular lattice with two shorter bonds and one longer bond. It shows a two-step magnetic phase transition at [Formula: see text] K and [Formula: see text] K at zero magnetic field, characteristic of an easy-axis anisotropy. In the magnetization curves, a series of magnetic phase transitions was observed such as an up-up-down phase at [Formula: see text] T with 1/3 of the saturation magnetization (M sat) and an oblique phase at [Formula: see text] T with [Formula: see text]/3 M sat. Intriguingly, the magnetic phase transition below T N2 is in tandem with the ferroelectricity, which demonstrates multiferroic behaviors. Moreover, the multiferroic phase persists in all magnetically ordered phases regardless of the spin structure. The comparison between the phase diagrams of Sr3NiNb2O9 and its sister compound with an equilateral triangular lattice antiferromagnet Ba3NiNb2O9 (Hwang et al 2012 Phys. Rev. Lett. 109 257205), illustrates how a small imbalance among exchange interactions change the magnetic ground states of the TLAFs.
View details for DOI 10.1088/0953-8984/28/47/476004
View details for Web of Science ID 000385448300004
View details for PubMedID 27661860
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Ultrathin Films.
ACS nano
2016; 10 (11): 9938-9947
Abstract
Large biaxial strain is a promising route to tune the functionalities of oxide thin films. However, large strain is often not fully realized due to the formation of misfit dislocations at the film/substrate interface. In this work, we examine the growth of strained ceria (CeO2) thin films on (001)-oriented single crystal yttria-stabilized zirconia (YSZ) via pulsed-laser deposition. By varying the film thickness systematically between 1 and 430 nm, we demonstrate that ultrathin ceria films are coherently strained to the YSZ substrate for thicknesses up to 2.7 nm, despite the large lattice mismatch (∼5%). The coherency is confirmed by both X-ray diffraction and high-resolution transmission electron microscopy. This thickness is several times greater than the predicted equilibrium critical thickness. Partial strain relaxation is achieved by forming semirelaxed surface islands rather than by directly nucleating dislocations. In situ reflective high-energy electron diffraction during growth confirms the transition from 2-D (layer-by-layer) to 3-D (island) at a film thickness of ∼1 nm, which is further supported by atomic force microscopy. We propose that dislocations likely nucleate near the surface islands and glide to the film/substrate interface, as evidenced by the presence of 60° dislocations. An improved understanding of growing oxide thin films with a large misfit lays the foundation to systematically explore the impact of strain and dislocations on properties such as ionic transport and redox chemistry.
View details for PubMedID 27934073
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Growth of Highly Strained CeO2 Ultrathin Films
ACS NANO
2016; 10 (11): 9938-9947
Abstract
Large biaxial strain is a promising route to tune the functionalities of oxide thin films. However, large strain is often not fully realized due to the formation of misfit dislocations at the film/substrate interface. In this work, we examine the growth of strained ceria (CeO2) thin films on (001)-oriented single crystal yttria-stabilized zirconia (YSZ) via pulsed-laser deposition. By varying the film thickness systematically between 1 and 430 nm, we demonstrate that ultrathin ceria films are coherently strained to the YSZ substrate for thicknesses up to 2.7 nm, despite the large lattice mismatch (∼5%). The coherency is confirmed by both X-ray diffraction and high-resolution transmission electron microscopy. This thickness is several times greater than the predicted equilibrium critical thickness. Partial strain relaxation is achieved by forming semirelaxed surface islands rather than by directly nucleating dislocations. In situ reflective high-energy electron diffraction during growth confirms the transition from 2-D (layer-by-layer) to 3-D (island) at a film thickness of ∼1 nm, which is further supported by atomic force microscopy. We propose that dislocations likely nucleate near the surface islands and glide to the film/substrate interface, as evidenced by the presence of 60° dislocations. An improved understanding of growing oxide thin films with a large misfit lays the foundation to systematically explore the impact of strain and dislocations on properties such as ionic transport and redox chemistry.
View details for DOI 10.1021/acsnano.6b04081
View details for Web of Science ID 000388913100022
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Aging, memory, and nonhierarchical energy landscape of spin jam
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2016; 113 (42): 11806-11810
Abstract
The notion of complex energy landscape underpins the intriguing dynamical behaviors in many complex systems ranging from polymers, to brain activity, to social networks and glass transitions. The spin glass state found in dilute magnetic alloys has been an exceptionally convenient laboratory frame for studying complex dynamics resulting from a hierarchical energy landscape with rugged funnels. Here, we show, by a bulk susceptibility and Monte Carlo simulation study, that densely populated frustrated magnets in a spin jam state exhibit much weaker memory effects than spin glasses, and the characteristic properties can be reproduced by a nonhierarchical landscape with a wide and nearly flat but rough bottom. Our results illustrate that the memory effects can be used to probe different slow dynamics of glassy materials, hence opening a window to explore their distinct energy landscapes.
View details for DOI 10.1073/pnas.1608057113
View details for Web of Science ID 000385610400061
View details for PubMedID 27698141
View details for PubMedCentralID PMC5081640
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Thermally induced crystallization in NbO2 thin films
SCIENTIFIC REPORTS
2016; 6
View details for DOI 10.1038/srep34294
View details for Web of Science ID 000384178900001
View details for PubMedID 27682633
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thin films.
Scientific reports
2016; 6: 34294-?
Abstract
Niobium dioxide can exhibit negative differential resistance (NDR) in metal-insulator-metal (MIM) devices, which has recently attracted significant interest for its potential applications as a highly non-linear selector element in emerging nonvolatile memory (NVM) and as a locally-active element in neuromorphic circuits. In order to further understand the processing of this material system, we studied the effect of thermal annealing on a 15 nm thick NbO2 thin film sandwiched inside a nanoscale MIM device and compared it with 180 nm thick blanket NbOx (x = 2 and 2.5) films deposited on a silicon dioxide surface as references. A systematic transmission electron microscope (TEM) study revealed a similar structural transition from amorphous to a distorted rutile structure in both cases, with a transition temperature of 700 °C for the NbO2 inside the MIM device and a slightly higher transition temperature of 750 °C for the reference NbO2 film. Quantitative composition analysis from electron energy loss spectroscopy (EELS) showed the stoichiometry of the nominal 15 nm NbO2 layer in the as-fabricated MIM device deviated from the target 1:2 ratio because of an interaction with the electrode materials, which was more prominent at elevated annealing temperature.
View details for DOI 10.1038/srep34294
View details for PubMedID 27682633
View details for PubMedCentralID PMC5041100
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The dissipation of field emitting carbon nanotubes in an oxygen environment as revealed by in situ transmission electron microscopy
NANOSCALE
2016; 8 (36): 16405-16415
View details for DOI 10.1039/c6nr06231h
View details for Web of Science ID 000384531600035
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The dissipation of field emitting carbon nanotubes in an oxygen environment as revealed by in situ transmission electron microscopy.
Nanoscale
2016; 8 (36): 16405-16415
Abstract
In this work, we report the first direct experimental observations of carbon nanotubes (CNT) field emitting in an oxygen environment, using aberration-corrected environmental transmission electron microscopy in combination with an electrical biasing specimen holder under low-dose, field-free imaging conditions. Our studies show that while the CNTs remain stable during high vacuum field emission, they experience abrupt decreases in length, also termed "burn-back", when field-emitting in an oxygen environment at around 30 Pa pressure. Furthermore, we perform correlative field-free and aberration-corrected, high-resolution transmission electron microscopy imaging to understand how the structure of the CNTs - particularly the opening of the nanotube caps - is influenced by its gas environment during field emission. This work provides significant insight into the mechanism of carbon nanotube behavior under non-ideal field emission conditions.
View details for PubMedID 27714121
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Reconstructing solute-induced phase transformations within individual nanocrystals
NATURE MATERIALS
2016; 15 (7): 768-?
Abstract
Strain and defects can significantly impact the performance of functional nanomaterials. This effect is well exemplified by energy storage systems, in which structural changes such as volume expansion and defect generation govern the phase transformations associated with charging and discharging. The rational design of next-generation storage materials therefore depends crucially on understanding the correlation between the structure of individual nanoparticles and their solute uptake and release. Here, we experimentally reconstruct the spatial distribution of hydride phases within individual palladium nanocrystals during hydrogen absorption, using a combination of electron spectroscopy, dark-field imaging, and electron diffraction in an environmental transmission electron microscope. We show that single-crystalline cubes and pyramids exhibit a uniform hydrogen distribution at equilibrium, whereas multiply twinned icosahedra exclude hydrogen from regions of high compressive strains. Our technique offers unprecedented insight into nanoscale phase transformations in reactive environments and can be extended to a variety of functional nanomaterials.
View details for DOI 10.1038/NMAT4620
View details for Web of Science ID 000378347800027
View details for PubMedID 27088234
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Torsional Deformations in Subnanometer MoS Interconnecting Wires
NANO LETTERS
2016; 16 (2): 1210-1217
Abstract
We use aberration-corrected transmission electron microscopy to track the real time atomic level torsional dynamics of subnanometer wires of MoS interconnecting monolayer regions of MoS2. An in situ heating holder is used inside the transmission electron microscope to raise the temperature of the sample to 400 °C to increase crystallization rates of the wires and reduce contamination effects. Frequent rotational twisting of the MoS wire is captured, demonstrating elastic torsional deformation of the MoS wires. We show that torsional rotations of the crystal structure of the MoS wires depend upon the specific atomic structure of the anchored sections of the suspended wire and the number of unit cells that make up the wire length. Elastic torsional flexibility of the MoS wires is revealed to help their self-adapting connectivity during the structural changes. Plastic torsional deformation is also seen for MoS wires that contain defects in their crystal structure, which produce small scale rotational disorder within the wires. Upon removal of the defects, the wire returns back to pristine form. These results provide detailed insights into how the atomic structure of the anchoring site significantly influences the nanowire configurations relative to the monolayered MoS2.
View details for DOI 10.1021/acs.nanolett.5b04507
View details for Web of Science ID 000370215200058
View details for PubMedID 26785319
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Oxidation of Carbon Nanotubes in an Ionizing Environment
NANO LETTERS
2016; 16 (2): 856-863
Abstract
In this work, we present systematic studies on how an illuminating electron beam which ionizes molecular gas species can influence the mechanism of carbon nanotube oxidation in an environmental transmission electron microscope (ETEM). We found that preferential attack of the nanotube tips is much more prevalent than for oxidation in a molecular gas environment. We establish the cumulative electron doses required to damage carbon nanotubes from 80 keV electron beam irradiation in gas versus in high vacuum. Our results provide guidelines for the electron doses required to study carbon nanotubes within or without a gas environment, to determine or ameliorate the influence of the imaging electron beam. This work has important implications for in situ studies as well as for the oxidation of carbon nanotubes in an ionizing environment such as that occurring during field emission.
View details for DOI 10.1021/acs.nanolett.5b03035
View details for Web of Science ID 000370215200005
View details for PubMedID 26726919
View details for PubMedCentralID PMC4859757
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Chemical and Phase Evolution of Amorphous Molybdenum Sulfide Catalysts for Electrochemical Hydrogen Production.
ACS nano
2016; 10 (1): 624-632
Abstract
Amorphous MoSx is a highly active, earth-abundant catalyst for the electrochemical hydrogen evolution reaction. Previous studies have revealed that this material initially has a composition of MoS3, but after electrochemical activation, the surface is reduced to form an active phase resembling MoS2 in composition and chemical state. However, structural changes in the MoSx catalyst and the mechanism of the activation process remain poorly understood. In this study, we employ transmission electron microscopy (TEM) to image amorphous MoSx catalysts activated under two hydrogen-rich conditions: ex situ in an electrochemical cell and in situ in an environmental TEM. For the first time, we directly observe the formation of crystalline domains in the MoSx catalyst after both activation procedures as well as spatially localized changes in the chemical state detected via electron energy loss spectroscopy. Using density functional theory calculations, we investigate the mechanisms for this phase transformation and find that the presence of hydrogen is critical for enabling the restructuring process. Our results suggest that the surface of the amorphous MoSx catalyst is dynamic: while the initial catalyst activation forms the primary active surface of amorphous MoS2, continued transformation to the crystalline phase during electrochemical operation could contribute to catalyst deactivation. These results have important implications for the application of this highly active electrocatalyst for sustainable H2 generation.
View details for DOI 10.1021/acsnano.5b05652
View details for PubMedID 26624225
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Rapid genome reshaping by multiple-gene loss after whole-genome duplication in teleost fish suggested by mathematical modeling
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2015; 112 (48): 14918-14923
View details for DOI 10.1073/pnas.1507669112
View details for Web of Science ID 000365988900056
View details for PubMedID 26578810
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Rotating Anisotropic Crystalline Silicon Nanoclusters in Graphene
ACS NANO
2015; 9 (10): 9497-9506
Abstract
The atomic structure and dynamics of silicon nanoclusters covalently bonded to graphene are studied using aberration-corrected transmission electron microscopy. We show that as the cluster size increases to 4-10 atoms, ordered crystalline cubic phases start to emerge. Anisotropic crystals are formed due to higher stability of the Si-C bond under electron beam irradiation compared to the Si-Si bond. Dynamics of the anisotropic crystalline Si nanoclusters reveal that they can rotate perpendicular to the graphene plane, with oscillations between the two geometric configurations driven by local volume constraints. These results provide important insights into the crystalline phases of clusters of inorganic dopants in graphene at the intermediate size range between isolated single atoms and larger bulk 2D forms.
View details for DOI 10.1021/acsnano.5b03476
View details for Web of Science ID 000363915300008
View details for PubMedID 26207802
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High-Density 2D Homo- and Hetero- Plasmonic Dimers with Universal Sub-10-nm Gaps
ACS NANO
2015; 9 (9): 9331-9339
Abstract
Fabrication of high-density plasmonic dimers on a large (wafer) scale is crucial for applications in surface-enhanced spectroscopy, bio- and molecular sensing, and optoelectronics. Here, we present an experimental approach based on nanoimprint lithography and shadow evaporation that allows for the fabrication of high-density, large-scale homo- (Au-Au and Ag-Ag) and hetero- (Au-Ag) dimer substrates with precise and consistent sub-10-nm gaps. We performed scanning electron, scanning transmission electron, and atomic force microscopy studies along with a complete electron energy-loss spectroscopy (EELS) characterization. We observed distinct plasmonic modes on these dimers, which are well interpreted by finite-difference time-domain (FDTD) and plasmon hybridization calculations.
View details for DOI 10.1021/acsnano.5b03090
View details for Web of Science ID 000361935800073
View details for PubMedID 26202803
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Control of Rubrene Polymorphs via Polymer Binders: Applications in Organic Field-Effect Transistors
CHEMISTRY OF MATERIALS
2015; 27 (11): 3979-3987
View details for DOI 10.1021/acs.chemmater.5b00884
View details for Web of Science ID 000356202800026
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Large-Area Assembly of Densely Aligned Single-Walled Carbon Nanotubes Using Solution Shearing and Their Application to Field-Effect Transistors
ADVANCED MATERIALS
2015; 27 (16): 2656-2662
Abstract
Dense alignment of single-walled carbon nanotubes over a large area is demonstrated using a novel solution-shearing technique. A density of 150-200 single-walled carbon nanotubes per micro-meter is achieved with a current density of 10.08 μA μm(-1) at VDS = -1 V. The on-current density is improved by a factor of 45 over that of random-network single-walled carbon nanotubes.
View details for DOI 10.1002/adma.201405289
View details for PubMedID 25788393
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A correlative optical microscopy and scanning electron microscopy approach to locating nanoparticles in brain tumors.
Micron
2015; 68: 70-76
Abstract
The growing use of nanoparticles in biomedical applications, including cancer diagnosis and treatment, demands the capability to exactly locate them within complex biological systems. In this work a correlative optical and scanning electron microscopy technique was developed to locate and observe multi-modal gold core nanoparticle accumulation in brain tumor models. Entire brain sections from mice containing orthotopic brain tumors injected intravenously with nanoparticles were imaged using both optical microscopy to identify the brain tumor, and scanning electron microscopy to identify the individual nanoparticles. Gold-based nanoparticles were readily identified in the scanning electron microscope using backscattered electron imaging as bright spots against a darker background. This information was then correlated to determine the exact location of the nanoparticles within the brain tissue. The nanoparticles were located only in areas that contained tumor cells, and not in the surrounding healthy brain tissue. This correlative technique provides a powerful method to relate the macro- and micro-scale features visible in light microscopy with the nanoscale features resolvable in scanning electron microscopy.
View details for DOI 10.1016/j.micron.2014.09.004
View details for PubMedID 25464144
View details for PubMedCentralID PMC4262686
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Theranostic mesoporous silica nanoparticles biodegrade after pro-survival drug delivery and ultrasound/magnetic resonance imaging of stem cells.
Theranostics
2015; 5 (6): 631-642
Abstract
Increasing cell survival in stem cell therapy is an important challenge for the field of regenerative medicine. Here, we report theranostic mesoporous silica nanoparticles that can increase cell survival through both diagnostic and therapeutic approaches. First, the nanoparticle offers ultrasound and MRI signal to guide implantation into the peri-infarct zone and away from the most necrotic tissue. Second, the nanoparticle serves as a slow release reservoir of insulin-like growth factor (IGF)-a protein shown to increase cell survival. Mesenchymal stem cells labeled with these nanoparticles had detection limits near 9000 cells with no cytotoxicity at the 250 µg/mL concentration required for labeling. We also studied the degradation of the nanoparticles and showed that they clear from cells in approximately 3 weeks. The presence of IGF increased cell survival up to 40% (p<0.05) versus unlabeled cells under in vitro serum-free culture conditions.
View details for DOI 10.7150/thno.11389
View details for PubMedID 25825602
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Designing Active and Stable Silicon Photocathodes for Solar Hydrogen Production Using Molybdenum Sulfide Nanomaterials
ADVANCED ENERGY MATERIALS
2014; 4 (18)
View details for DOI 10.1002/aenm.201400739
View details for Web of Science ID 000346983100007
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Doping against the Native Propensity of MoS2: Degenerate Hole Doping by Cation Substitution
NANO LETTERS
2014; 14 (12): 6976-6982
Abstract
Layered transition metal dichalcogenides (TMDs) draw much attention as the key semiconducting material for two-dimensional electrical, optoelectronic, and spintronic devices. For most of these applications, both n- and p-type materials are needed to form junctions and support bipolar carrier conduction. However, typically only one type of doping is stable for a particular TMD. For example, molybdenum disulfide (MoS2) is natively an n-type presumably due to omnipresent electron-donating sulfur vacancies, and stable/controllable p-type doping has not been achieved. The lack of p-type doping hampers the development of charge-splitting p-n junctions of MoS2, as well as limits carrier conduction to spin-degenerate conduction bands instead of the more interesting, spin-polarized valence bands. Traditionally, extrinsic p-type doping in TMDs has been approached with surface adsorption or intercalation of electron-accepting molecules. However, practically stable doping requires substitution of host atoms with dopants where the doping is secured by covalent bonding. In this work, we demonstrate stable p-type conduction in MoS2 by substitutional niobium (Nb) doping, leading to a degenerate hole density of ∼ 3 × 10(19) cm(-3). Structural and X-ray techniques reveal that the Nb atoms are indeed substitutionally incorporated into MoS2 by replacing the Mo cations in the host lattice. van der Waals p-n homojunctions based on vertically stacked MoS2 layers are fabricated, which enable gate-tunable current rectification. A wide range of microelectronic, optoelectronic, and spintronic devices can be envisioned from the demonstrated substitutional bipolar doping of MoS2. From the miscibility of dopants with the host, it is also expected that the synthesis technique demonstrated here can be generally extended to other TMDs for doping against their native unipolar propensity.
View details for DOI 10.1021/nl503251h
View details for Web of Science ID 000346322800035
View details for PubMedID 25420217
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Redox-triggered self-assembly of gadolinium-based MRI probes for sensing reducing environment.
Bioconjugate chemistry
2014; 25 (8): 1526-1536
Abstract
Controlled self-assembly of small molecule gadolinium (Gd) complexes into nanoparticles (GdNPs) is emerging as an effective approach to design activatable magnetic resonance imaging (MRI) probes and amplify the r₁ relaxivity. Herein, we employ a reduction-controlled macrocyclization reaction and self-assembly to develop a redox activated Gd-based MRI probe for sensing a reducing environment. Upon disulfide reduction at physiological conditions, an acyclic contrast agent 1 containing dual Gd-chelates undergoes intramolecular macrocyclization to form rigid and hydrophobic macrocycles, which subsequently self-assemble into GdNPs, resulting in a ∼60% increase in r₁ relaxivity at 0.5 T. Probe 1 has high r₁ relaxivity (up to 34.2 mM(-1) s(-1) per molecule at 0.5 T) upon activation, and also shows a high sensitivity and specificity for MR detection of thiol-containing biomolecules.
View details for DOI 10.1021/bc500254g
View details for PubMedID 24992373
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Ultrafast polarization response of an optically trapped single ferroelectric nanowire.
Nano letters
2014; 14 (8): 4322-4327
Abstract
One-dimensional potassium niobate nanowires are of interest as building blocks in integrated piezoelectric devices, exhibiting large nonlinear optical and piezoelectric responses. Here we present femtosecond measurements of light-induced polarization dynamics within an optically trapped ferroelectric nanowire, using the second-order nonlinear susceptibility as a real-time structural probe. Large amplitude, reversible modulations of the nonlinear susceptibility are observed within single nanowires at megahertz repetition rates, developing on few-picosecond time-scales, associated with anomalous coupling of light into the nanowire.
View details for DOI 10.1021/nl5011228
View details for PubMedID 25051318
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Redox-Triggered Self-Assembly of Gadolinium-Based MRI Probes for Sensing Reducing Environment
BIOCONJUGATE CHEMISTRY
2014; 25 (8): 1526-1536
Abstract
Controlled self-assembly of small molecule gadolinium (Gd) complexes into nanoparticles (GdNPs) is emerging as an effective approach to design activatable magnetic resonance imaging (MRI) probes and amplify the r₁ relaxivity. Herein, we employ a reduction-controlled macrocyclization reaction and self-assembly to develop a redox activated Gd-based MRI probe for sensing a reducing environment. Upon disulfide reduction at physiological conditions, an acyclic contrast agent 1 containing dual Gd-chelates undergoes intramolecular macrocyclization to form rigid and hydrophobic macrocycles, which subsequently self-assemble into GdNPs, resulting in a ∼60% increase in r₁ relaxivity at 0.5 T. Probe 1 has high r₁ relaxivity (up to 34.2 mM(-1) s(-1) per molecule at 0.5 T) upon activation, and also shows a high sensitivity and specificity for MR detection of thiol-containing biomolecules.
View details for DOI 10.1021/bc500254g
View details for Web of Science ID 000340735900020
View details for PubMedCentralID PMC4140571
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Tuning Interlayer Coupling in Large-Area Heterostructures with CVD-Grown MoS2 and WS2 Monolayers
NANO LETTERS
2014; 14 (6): 3185-3190
Abstract
Band offsets between different monolayer transition metal dichalcogenides are expected to efficiently separate charge carriers or rectify charge flow, offering a mechanism for designing atomically thin devices and probing exotic two-dimensional physics. However, developing such large-area heterostructures has been hampered by challenges in synthesis of monolayers and effectively coupling neighboring layers. Here, we demonstrate large-area (>tens of micrometers) heterostructures of CVD-grown WS2 and MoS2 monolayers, where the interlayer interaction is externally tuned from noncoupling to strong coupling. Following this trend, the luminescence spectrum of the heterostructures evolves from an additive line profile where each layer contributes independently to a new profile that is dictated by charge transfer and band normalization between the WS2 and MoS2 layers. These results and findings open up venues to creating new material systems with rich functionalities and novel physical effects.
View details for DOI 10.1021/nl500515q
View details for Web of Science ID 000337337100032
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Gareth Thomas (9 August 1932-6 February 2014).
Microscopy (Oxford, England)
2014; 63 (3): 175-6
View details for DOI 10.1093/jmicro/dfu018
View details for PubMedID 24928843
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RESET-first unipolar resistance switching behavior in annealed Nb2O5 films
THIN SOLID FILMS
2014; 558: 423-429
View details for DOI 10.1016/j.tsf.2014.03.003
View details for Web of Science ID 000334314100066
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The Stanford Nanocharacterization Laboratory (SNL) and Recent Applications of an Aberration-Corrected Environmental Transmission Electron Microscope
ADVANCED ENGINEERING MATERIALS
2014; 16 (5): 476-481
View details for DOI 10.1002/adem.201400015
View details for Web of Science ID 000337582600001
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The Stanford Nanocharacterization Laboratory (SNL) and Recent Applications of an Aberration-Corrected Environmental Transmission Electron Microscope.
Advanced engineering materials
2014; 16 (5): 476-481
Abstract
This article describes the establishment, over a period of ten years or so, of a multi-user, institution-wide facility for the characterization of materials and devices at the nano-scale. Emphasis is placed on the type of equipment that we have found to be most useful for our users, and the business strategy that maintains its operations. A central component of our facility is an aberration-corrected environmental transmission electron microscope and its application is summarized in the studies of plasmon energies of silver nanoparticles, the band gap of PbS quantum dots, atomic site occupancy near grain boundaries in yttria stabilized zirconia, the lithiation of silicon nanoparticles, in situ observations on carbon nanotube oxidation and the electron tomography of varicella zoster virus nucleocapsids.
View details for PubMedID 25364299
View details for PubMedCentralID PMC4215512
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A tunable silk-alginate hydrogel scaffold for stem cell culture and transplantation.
Biomaterials
2014; 35 (12): 3736-3743
Abstract
One of the major challenges in regenerative medicine is the ability to recreate the stem cell niche, which is defined by its signaling molecules, the creation of cytokine gradients, and the modulation of matrix stiffness. A wide range of scaffolds has been developed in order to recapitulate the stem cell niche, among them hydrogels. This paper reports the development of a new silk-alginate based hydrogel with a focus on stem cell culture. This biocomposite allows to fine tune its elasticity during cell culture, addressing the importance of mechanotransduction during stem cell differentiation. The silk-alginate scaffold promotes adherence of mouse embryonic stem cells and cell survival upon transplantation. In addition, it has tunable stiffness as function of the silk-alginate ratio and the concentration of crosslinker - a characteristic that is very hard to accomplish in current hydrogels. The hydrogel and the presented results represents key steps on the way of creating artificial stem cell niche, opening up new paths in regenerative medicine.
View details for DOI 10.1016/j.biomaterials.2014.01.029
View details for PubMedID 24484675
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Effects of germanium incorporation on optical performances of silicon germanium passive devices for group-IV photonic integrated circuits
PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS
2014; 12 (1): 54-68
View details for DOI 10.1016/j.photonics.2013.07.012
View details for Web of Science ID 000332593700007
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Controlling sulphur precursor addition for large single crystal domains of WS2
NANOSCALE
2014; 6 (20): 12096-12103
View details for DOI 10.1039/c4nr04091k
View details for Web of Science ID 000343000800064
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Approaching the limits of dielectric breakdown for SiO2 films deposited by plasma-enhanced atomic layer deposition
ACTA MATERIALIA
2013; 61 (20): 7660-7670
View details for DOI 10.1016/j.actamat.2013.09.003
View details for Web of Science ID 000328179700013
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In situ high-resolution transmission electron microscopy of material reactions
MRS BULLETIN
2013; 38 (12): 1065-1071
View details for DOI 10.1557/mrs.2013.285
View details for Web of Science ID 000330346500018
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HREM analysis of graphite-encapsulated metallic nanoparticles for possible medical applications.
Ultramicroscopy
2013; 134: 167-174
Abstract
High resolution electron microscopy has been applied to study the structure of metallic nanoparticles. These have sparked considerable interest as contrast agents in the field of biological imaging, including in magnetic resonance imaging (MRI) and computed tomography (CT). Here, we describe a method of synthesizing sub-10nm superparamagnetic metal and alloy nanoparticles by reduction of metallic salts. Annealing at 900°C in a methane/hydrogen environment forms a thin graphitic-carbon shell which is expected to improve stability, biocompatibility, and functionalization. Subsequent high resolution electron microscopy verifies graphitization and allows for crystallographic analysis. Most particles consist of single crystals in the phase predicted for the bulk material at the annealing temperature. Electron energy loss spectroscopy, energy dispersive X-ray spectroscopy and lattice constant measurements show large variation in composition for alloy nanoparticles from a single synthesis. The magnetization relaxation time (T2) measurements demonstrate that Fe and AuFe nanoparticles compete with commercially available iron oxide MRI contrast agents. X-ray attenuation measurements of an AuFe alloy nanoparticle solution gave a relative radiodensity of 280 Hounsfield Units, demonstrating promise as a dual-purpose contrast agent in CT and MRI. Long term stability in an atmospheric environment was also tested, with no signs of corrosion or oxidation after several years of storage.
View details for DOI 10.1016/j.ultramic.2013.05.006
View details for PubMedID 23809196
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A scanning transmission electron microscopy approach to analyzing large volumes of tissue to detect nanoparticles.
Microscopy and microanalysis
2013; 19 (5): 1290-1297
Abstract
The use of nanoparticles for the diagnosis and treatment of cancer requires the complete characterization of their toxicity, including accurately locating them within biological tissues. Owing to their size, traditional light microscopy techniques are unable to resolve them. Transmission electron microscopy provides the necessary spatial resolution to image individual nanoparticles in tissue, but is severely limited by the very small analysis volume, usually on the order of tens of cubic microns. In this work, we developed a scanning transmission electron microscopy (STEM) approach to analyze large volumes of tissue for the presence of polyethylene glycol-coated Raman-active-silica-gold-nanoparticles (PEG-R-Si-Au-NPs). This approach utilizes the simultaneous bright and dark field imaging capabilities of STEM along with careful control of the image contrast settings to readily identify PEG-R-Si-Au-NPs in mouse liver tissue without the need for additional time-consuming analytical characterization. We utilized this technique to analyze 243,000 μm3 of mouse liver tissue for the presence of PEG-R-Si-Au-NPs. Nanoparticles injected into the mice intravenously via the tail vein accumulated in the liver, whereas those injected intrarectally did not, indicating that they remain in the colon and do not pass through the colon wall into the systemic circulation.
View details for DOI 10.1017/S143192761300192X
View details for PubMedID 23803218
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Atomic Scale Verification of Oxide-Ion Vacancy Distribution near a Single Grain Boundary in YSZ.
Scientific reports
2013; 3: 2680-?
Abstract
This study presents atomic scale characterization of grain boundary defect structure in a functional oxide with implications for a wide range of electrochemical and electronic behavior. Indeed, grain boundary engineering can alter transport and kinetic properties by several orders of magnitude. Here we report experimental observation and determination of oxide-ion vacancy concentration near the Σ13 (510)/[001] symmetric tilt grain-boundary of YSZ bicrystal using aberration-corrected TEM operated under negative spherical aberration coefficient imaging condition. We show significant oxygen deficiency due to segregation of oxide-ion vacancies near the grain-boundary core with half-width < 0.6 nm. Electron energy loss spectroscopy measurements with scanning TEM indicated increased oxide-ion vacancy concentration at the grain boundary core. Oxide-ion density distribution near a grain boundary simulated by molecular dynamics corroborated well with experimental results. Such column-by-column quantification of defect concentration in functional materials can provide new insights that may lead to engineered grain boundaries designed for specific functionalities.
View details for DOI 10.1038/srep02680
View details for PubMedID 24042150
View details for PubMedCentralID PMC3775093
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Oxidation Studies of Carbon Nanotubes for Applications as X-Ray Field Emitters Using an Aberration-Corrected, Environmental TEM.
Microscopy and microanalysis
2013; 19: 466-467
View details for PubMedID 25552911
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Atomic layer deposition of CdO and CdxZn1-xO films
MATERIALS CHEMISTRY AND PHYSICS
2013; 140 (2-3): 465-471
View details for DOI 10.1016/j.matchemphys.2013.03.038
View details for Web of Science ID 000320837700008
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Amorphous thin film TaWSiC as a diffusion barrier for copper interconnects
APPLIED PHYSICS LETTERS
2013; 103 (2)
View details for DOI 10.1063/1.4813396
View details for Web of Science ID 000321761000036
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Advanced Characterization Techniques for Nanoparticles for Cancer Research: Applications of SEM and NanoSIMS for Locating Au Nanoparticles in Cells.
Materials Research Society symposia proceedings. Materials Research Society
2013; 1569: 157-163
Abstract
The ability of nano secondary ion mass spectrometry (NanoSIMS) to locate and analyze Raman active gold core nanoparticles (R-AuNPs) in a biological system is compared with the standard analysis using the scanning electron microscope (SEM). The same cell with R-AuNPs on and inside the macrophage was analyzed with both techniques to directly compare them. SEM analysis showed a large number of nanoparticles within the cell. Subsequent NanoSIMS analysis showed fewer R-AuNPs with lower spatial resolution. SEM was determined to be superior to NanoSIMS for the analysis of inorganic nanoparticles in complex biological systems.
View details for PubMedID 25364091
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Aberration-Corrected TEM Imaging of Oxygen Occupancy in YSZ
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
2013; 4 (7): 1156-1160
Abstract
We present atomic-scale imaging of oxygen columns and show quantitative analysis on the occupancy of the columns in yttria-stabilized zirconia (YSZ) using aberration-corrected TEM operated under the negative Cs condition. Also, individual contributions both from oxygen column occupancy and the static displacement of oxygen atoms due to occupancy change to the observed column intensities of TEM images were systematically investigated using HRTEM simulation. We found that oxygen column intensity is governed primarily by column occupancy rather than by static displacement of oxygen atoms. Utilizing the aberration-corrected TEM capability and HRTEM simulation results, we experimentally verified that oxygen vacancies segregate near the single grain boundary of a YSZ bicrystal. The methodology and the high spatial resolution characterization tool employed in the present study provide insights into the distribution of oxygen vacancies in the bulk as well as near grain boundaries and pave the way for further investigation and atomic-scale analysis in other important oxide materials.
View details for DOI 10.1021/jz4002423
View details for Web of Science ID 000317317500017
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Automatic Segmentation of Scaling in 2-D Psoriasis Skin Images
IEEE TRANSACTIONS ON MEDICAL IMAGING
2013; 32 (4): 719-730
Abstract
Psoriasis is a chronic inflammatory skin disease that affects over 3% of the population. Various methods are currently used to evaluate psoriasis severity and to monitor therapeutic response. The PASI system of scoring is widely used for evaluating psoriasis severity. It employs a visual analogue scale to score the thickness, redness (erythema), and scaling of psoriasis lesions. However, PASI scores are subjective and suffer from poor inter- and intra-observer concordance. As an integral part of developing a reliable evaluation method for psoriasis, an algorithm is presented for segmenting scaling in 2-D digital images. The algorithm is believed to be the first to localize scaling directly in 2-D digital images. The scaling segmentation problem is treated as a classification and parameter estimation problem. A Markov random field (MRF) is used to smooth a pixel-wise classification from a support vector machine (SVM) that utilizes a feature space derived from image color and scaling texture. The training sets for the SVM are collected directly from the image being analyzed giving the algorithm more resilience to variations in lighting and skin type. The algorithm is shown to give reliable segmentation results when evaluated with images with different lighting conditions, skin types, and psoriasis types.
View details for DOI 10.1109/TMI.2012.2236349
View details for Web of Science ID 000318474700009
View details for PubMedID 23288330
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Observations of Carbon Nanotube Oxidation in an Aberration-Corrected Environmental Transmission Electron Microscope
ACS NANO
2013; 7 (3): 2566-2572
Abstract
We report the first direct study on the oxidation of carbon nanotubes at the resolution of an aberration-corrected environmental transmission electron microscope (ETEM), as we locate and identify changes in the same nanotubes as they undergo oxidation at increasing temperatures in situ in the ETEM. Contrary to earlier reports that CNT oxidation initiates at the end of the tube and proceeds along its length, our findings show that only the outside graphene layer is being removed and, on occasion, the interior inner wall is oxidized, presumably due to oxygen infiltrating into the hollow nanotube through an open end or breaks in the tube. We believe that this work provides the foundation for a greater scientific understanding of the mechanism underlying the nanotube oxidation process, as well as guidelines to manipulate the nanotubes' structure or prevent their oxidation.
View details for DOI 10.1021/nn305949h
View details for Web of Science ID 000316846700075
View details for PubMedID 23360330
View details for PubMedCentralID PMC3609878
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Spatial Variation of Available Electronic Excitations within Individual Quantum Dots
NANO LETTERS
2013; 13 (2): 716-721
Abstract
Quantum dots (QDs) allow for manipulation of the position and energy levels of electrons at sub-10 nm length scales through control of material chemistry, size, and shape. It is known from optical studies that the bandgap of semiconductor QDs increases as their size decreases due to the narrowing of the quantum confinement potential. The mechanism of quantum confinement also indicates that the localized properties within individual QDs should depend on their shape in addition to their size, but direct observations of this effect have proven challenging due to the limited spatial resolution of measurement techniques at this scale and the ability to remove contributions from the surroundings. Here we present experimental evidence of spatial variations in the lowest available electron transition energy within a series of single electrically isolated QDs due to a dome-shaped geometry, measured using electron energy-loss spectroscopy in a (scanning) transmission electron microscope [(S)TEM-EELS]. We observe a consistent increase in the energy onset of electronic excitations from the lateral center of the dot toward the edges, which we attribute purely to shape. This trend is in qualitative agreement with a simple quantum simulation of the local density of states in a dome-shaped QD.
View details for DOI 10.1021/nl304400c
View details for Web of Science ID 000315079500065
View details for PubMedID 23276278
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Codoping titanium dioxide nanowires with tungsten and carbon for enhanced photoelectrochemical performance.
Nature communications
2013; 4: 1723-?
Abstract
Recent density-functional theory calculations suggest that codoping TiO2 with donor-acceptor pairs is more effective than monodoping for improving photoelectrochemical water-splitting performance because codoping can reduce charge recombination, improve material quality, enhance light absorption and increase solubility limits of dopants. Here we report a novel ex-situ method to codope TiO2 with tungsten and carbon (W, C) by sequentially annealing W-precursor-coated TiO2 nanowires in flame and carbon monoxide gas. The unique advantages of flame annealing are that the high temperature (>1,000 °C) and fast heating rate of flame enable rapid diffusion of W into TiO2 without damaging the nanowire morphology and crystallinity. This is the first experimental demonstration that codoped TiO2:(W, C) nanowires outperform monodoped TiO2:W and TiO2:C and double the saturation photocurrent of undoped TiO2 for photoelectrochemical water splitting. Such significant performance enhancement originates from a greatly improved electrical conductivity and activity for oxygen-evolution reaction due to the synergistic effects of codoping.
View details for DOI 10.1038/ncomms2729
View details for PubMedID 23591890
- Locating and Characterizing Self-Assembled Gadolinium Chelate Nanoparticles in Stem Cells Using TEM 2013
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Codoping titanium dioxide nanowires with tungsten and carbon for enhanced photoelectrochemical performance.
Nature communications
2013; 4: 1723-?
Abstract
Recent density-functional theory calculations suggest that codoping TiO2 with donor-acceptor pairs is more effective than monodoping for improving photoelectrochemical water-splitting performance because codoping can reduce charge recombination, improve material quality, enhance light absorption and increase solubility limits of dopants. Here we report a novel ex-situ method to codope TiO2 with tungsten and carbon (W, C) by sequentially annealing W-precursor-coated TiO2 nanowires in flame and carbon monoxide gas. The unique advantages of flame annealing are that the high temperature (>1,000 °C) and fast heating rate of flame enable rapid diffusion of W into TiO2 without damaging the nanowire morphology and crystallinity. This is the first experimental demonstration that codoped TiO2:(W, C) nanowires outperform monodoped TiO2:W and TiO2:C and double the saturation photocurrent of undoped TiO2 for photoelectrochemical water splitting. Such significant performance enhancement originates from a greatly improved electrical conductivity and activity for oxygen-evolution reaction due to the synergistic effects of codoping.
View details for DOI 10.1038/ncomms2729
View details for PubMedID 23591890
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Amorphous Thin Film TaWSiC as a Diffusion Barrier for Copper Interconnects
Appl. Phys. Lett.
2013; 103: 22104
View details for DOI 10.1063/1.4813396
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Codoping Titanium Dioxide Nanowires with (W, C) for Enhancing Photoelectrochemical Performance
Nature Communications
2013; 4: 1723
View details for DOI 10.1038/ncomms2729
- Oxidation Studies of Carbon Nanotubes for Applications as X-Ray Field Emitters Using an Aberration-Corrected, Environmental TEM 2013
- Advanced Characterization Techniques for Nanoparticles for Cancer Research: Applications of SEM and NanoSIMS for Locating Au Nanoparticles in Cells 2013
- A Correlative Light Microscopy and Scanning Electron Microscopy Approach to Locating Raman Active Gold Core Nanoparticles in Tissue Sections 2013
- In Situ High-Resolution Transmission Electron Microscopy of Materials Reactions Mat. Res. Soc. Bull. 2013; 38: 1065-1071
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Atomic Scale Verification of Oxide-Ion Vacancy Distribution near a Single Grain Boundary in YSZ
Scientific Reports
2013; 3: 2680
View details for DOI 10.1038/srep02680
- HREM Analysis of Graphite-Encapsulated Metallic Nanoparticles for Possible Medical Applications Ultramicroscopy 2013; 134: 167-174
- A Scanning Transmission Electron Microscopy (STEM) Technique to Analyze ‘Large’ Volumes of Tissue to Detect Nanoparticles Microscopy and Microanalysis 2013; 5 (19): 1290-1297
- Chracterization of E-Beam Fabricated Gold Nanoparticles 2013
- NorTEMnet 2013 Workshop on Advanced Transmission Electron Microscopy 2013
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Observations of Carbon Nanotube Oxidation in an Aberration-Corrected, Environmental Transmission Electron Microscope
ACS nano
2013; 3 (7): 2566-2572
View details for DOI 10.1021/nn305949h
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Atomic scale verification of oxide-ion vacancy distribution near a single grain boundary in YSZ.
Scientific reports
2013; 3: 2680-?
Abstract
This study presents atomic scale characterization of grain boundary defect structure in a functional oxide with implications for a wide range of electrochemical and electronic behavior. Indeed, grain boundary engineering can alter transport and kinetic properties by several orders of magnitude. Here we report experimental observation and determination of oxide-ion vacancy concentration near the Σ13 (510)/[001] symmetric tilt grain-boundary of YSZ bicrystal using aberration-corrected TEM operated under negative spherical aberration coefficient imaging condition. We show significant oxygen deficiency due to segregation of oxide-ion vacancies near the grain-boundary core with half-width < 0.6 nm. Electron energy loss spectroscopy measurements with scanning TEM indicated increased oxide-ion vacancy concentration at the grain boundary core. Oxide-ion density distribution near a grain boundary simulated by molecular dynamics corroborated well with experimental results. Such column-by-column quantification of defect concentration in functional materials can provide new insights that may lead to engineered grain boundaries designed for specific functionalities.
View details for DOI 10.1038/srep02680
View details for PubMedID 24042150
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A Brain Tumor Molecular Imaging Strategy using a New Triple-Modality MRI-Photoacoustic-Raman Nanoparticle
Conference on Photons Plus Ultrasound - Imaging and Sensing
SPIE-INT SOC OPTICAL ENGINEERING. 2013
View details for DOI 10.1117/12.2001719
View details for Web of Science ID 000322832800007
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In Situ Cycle-by-Cycle Flash Annealing of Atomic Layer Deposited Materials
JOURNAL OF PHYSICAL CHEMISTRY C
2012; 116 (45): 24177-24183
View details for DOI 10.1021/jp308895e
View details for Web of Science ID 000311190800041
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Nickel Silicide Nanowire Arrays for Anti-Reflective Electrodes in Photovoltaics
ADVANCED FUNCTIONAL MATERIALS
2012; 22 (17): 3650-3657
View details for DOI 10.1002/adfm.201200398
View details for Web of Science ID 000308329800015
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Shape Matters: Intravital Microscopy Reveals Surprising Geometrical Dependence for Nanoparticles in Tumor Models of Extravasation
NANO LETTERS
2012; 12 (7): 3369-3377
Abstract
Delivery is one of the most critical obstacles confronting nanoparticle use in cancer diagnosis and therapy. For most oncological applications, nanoparticles must extravasate in order to reach tumor cells and perform their designated task. However, little understanding exists regarding the effect of nanoparticle shape on extravasation. Herein we use real-time intravital microscopic imaging to meticulously examine how two different nanoparticles behave across three different murine tumor models. The study quantitatively demonstrates that high-aspect ratio single-walled carbon nanotubes (SWNTs) display extravasational behavior surprisingly different from, and counterintuitive to, spherical nanoparticles although the nanoparticles have similar surface coatings, area, and charge. This work quantitatively indicates that nanoscale extravasational competence is highly dependent on nanoparticle geometry and is heterogeneous.
View details for DOI 10.1021/nl204175t
View details for Web of Science ID 000306296200004
View details for PubMedID 22650417
View details for PubMedCentralID PMC3495189
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Smart-cut layer transfer of single-crystal SiC using spin-on-glass
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
2012; 30 (4)
View details for DOI 10.1116/1.4734006
View details for Web of Science ID 000306750700046
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Photoacoustic Imaging of Mesenchymal Stem Cells in Living Mice via Silica-Coated Gold Nanorods
ACS NANO
2012; 6 (7): 5920-5930
Abstract
Improved imaging modalities are critically needed for optimizing stem cell therapy. Techniques with real-time content to guide and quantitate cell implantation are especially important in applications such as musculoskeletal regenerative medicine. Here, we report the use of silica-coated gold nanorods as a contrast agent for photoacoustic imaging and quantitation of mesenchymal stem cells in rodent muscle tissue. The silica coating increased the uptake of gold into the cell more than 5-fold, yet no toxicity or proliferation changes were observed in cells loaded with this contrast agent. Pluripotency of the cells was retained, and secretome analysis indicated that only IL-6 was disregulated more than 2-fold from a pool of 26 cytokines. The low background of the technique allowed imaging of down to 100,000 cells in vivo. The spatial resolution is 340 μm, and the temporal resolution is 0.2 s, which is at least an order of magnitude below existing cell imaging approaches. This approach has significant advantages over traditional cell imaging techniques like positron emission tomography and magnetic resonance imaging including real time monitoring of stem cell therapy.
View details for DOI 10.1021/nn302042y
View details for Web of Science ID 000306673800020
View details for PubMedID 22681633
View details for PubMedCentralID PMC3582222
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A brain tumor molecular imaging strategy using a new triple-modality MRI-photoacoustic-Raman nanoparticle
NATURE MEDICINE
2012; 18 (5): 829-U235
Abstract
The difficulty in delineating brain tumor margins is a major obstacle in the path toward better outcomes for patients with brain tumors. Current imaging methods are often limited by inadequate sensitivity, specificity and spatial resolution. Here we show that a unique triple-modality magnetic resonance imaging-photoacoustic imaging-Raman imaging nanoparticle (termed here MPR nanoparticle) can accurately help delineate the margins of brain tumors in living mice both preoperatively and intraoperatively. The MPRs were detected by all three modalities with at least a picomolar sensitivity both in vitro and in living mice. Intravenous injection of MPRs into glioblastoma-bearing mice led to MPR accumulation and retention by the tumors, with no MPR accumulation in the surrounding healthy tissue, allowing for a noninvasive tumor delineation using all three modalities through the intact skull. Raman imaging allowed for guidance of intraoperative tumor resection, and a histological correlation validated that Raman imaging was accurately delineating the brain tumor margins. This new triple-modality-nanoparticle approach has promise for enabling more accurate brain tumor imaging and resection.
View details for DOI 10.1038/nm.2721
View details for Web of Science ID 000303763500053
View details for PubMedID 22504484
View details for PubMedCentralID PMC3422133
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Aberration-Corrected Transmission Electron Microscopy of the Intergranular Phase in Magnetic Recording Media
NANO LETTERS
2012; 12 (5): 2595-2598
Abstract
In perpendicular hard disk memory media, nanometric magnetic Co-rich grains are separated by a ∼1 nm thick nonmagnetic and preferably amorphous intergranular phase (IP). Attempts at observing the IP structure at high resolution using TEM have been obstructed by the superposition of lattice fringes from the crystalline grains extending into the IP region in images. Here we present the first images of a magnetic recording medium produced using a spherical aberration-corrected TEM showing the true amorphous IP structure in contrast to the crystalline grains, allowing the accurate determination of the grain-IP interface and the grain and IP dimensions. It is shown that these aberration-corrected TEM images are functionally superior for analyzing certain features of the ultrahigh capacity data recording media.
View details for DOI 10.1021/nl301274x
View details for Web of Science ID 000303696400073
View details for PubMedID 22519694
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Oxygen Surface Exchange at Grain Boundaries of Oxide Ion Conductors
ADVANCED FUNCTIONAL MATERIALS
2012; 22 (5): 965-971
View details for DOI 10.1002/adfm.201101996
View details for Web of Science ID 000300931500008
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Interfacial Alloy Hydride Destabilization in Mg/Pd Thin Films
PHYSICAL REVIEW LETTERS
2012; 108 (10)
Abstract
Recently, a large increase in the equilibrium hydrogen pressure has been reported for MG thin films capped with a Pd layer. We show that this increase is due to intermixing of Mg and Pd, as opposed to a strain effect as previously claimed. Transmission electron microscopy and depth profiling x-ray photoemission spectroscopy are used to directly measure interfacial intermixing between Mg and Pd, and we find that intermixing and equilibrium hydrogen pressure both increase with annealing. We present a thermodynamic model of the effect of alloying on equilibrium pressure, and find that the observed equilibrium pressure increase is consistent with the observed thickness of the intermixed region, which is of the order of a few nm. We also show that stress measured during hydrogenation corresponds to a negligible increase in equilibrium pressure.
View details for DOI 10.1103/PhysRevLett.108.106102
View details for Web of Science ID 000301101200008
View details for PubMedID 22463426
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Effects of thermal cycling on microstructure and properties in Nitinol
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
2012; 532: 130-138
View details for DOI 10.1016/j.msea.2011.10.073
View details for Web of Science ID 000301160100020
- A Brain Tumor Molecular Imaging Strategy Using a Novel Triple Modality Nanoparticle Nature Medicine 2012; 18: 829-834
- Aberration Corrected Transmission Electron Microscopy of the Intergranular Phase in Magnetic Recording Media Nano Lett. 2012; 5 (12): 2595–2598
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Effect of crystallinity on proton conductivity in yttrium-doped barium zirconate thin films
SOLID STATE IONICS
2011; 198 (1): 39-46
View details for DOI 10.1016/j.ssi.2011.07.004
View details for Web of Science ID 000295892700007
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Scanning Transmission Electron Microscopy Analysis of Grain Structure in Perpendicular Magnetic Recording Media
NANO LETTERS
2011; 11 (9): 3751-3754
Abstract
The key component of a hard disk medium is a Co-based magnetic layer (ML) grown on a Ru seed layer. The ML nanostructure, composed of less than 10 nm grains, is believed to be controlled by this seed layer. We successfully used scanning transmission electron microscopy energy dispersive spectrometry simultaneous composition-based imaging and Moiré pattern analysis for determining the mutual structural and orientation relationship between the two layers revealing a grain-to-grain agreement. The method presented here can be utilized for observing structural correlations between consecutive polycrystalline thin film layers in general.
View details for DOI 10.1021/nl201784z
View details for Web of Science ID 000294790200041
View details for PubMedID 21806054
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Preclinical Evaluation of Raman Nanoparticle Biodistribution for their Potential Use in Clinical Endoscopy Imaging
SMALL
2011; 7 (15): 2232-2240
Abstract
Raman imaging offers unsurpassed sensitivity and multiplexing capabilities. However, its limited depth of light penetration makes direct clinical translation challenging. Therefore, a more suitable way to harness its attributes in a clinical setting would be to couple Raman spectroscopy with endoscopy. The use of an accessory Raman endoscope in conjunction with topically administered tumor-targeting Raman nanoparticles during a routine colonoscopy could offer a new way to sensitively detect dysplastic lesions while circumventing Raman's limited depth of penetration and avoiding systemic toxicity. In this study, the natural biodistribution of gold surface-enhanced Raman scattering (SERS) nanoparticles is evaluated by radiolabeling them with (64) Cu and imaging their localization over time using micropositron emission tomography (PET). Mice are injected either intravenously (IV) or intrarectally (IR) with approximately 100 microcuries (μCi) (3.7 megabecquerel (MBq)) of (64) Cu-SERS nanoparticles and imaged with microPET at various time points post injection. Quantitative biodistribution data are obtained as % injected dose per gram (%ID g(-1)) from each organ, and the results correlate well with the corresponding microPET images, revealing that IV-injected mice have significantly higher uptake (p < 0.05) in the liver (5 h = 8.96% ID g(-1); 24 h = 8.27% ID g(-1)) than IR-injected mice (5 h = 0.09% ID g(-1); 24 h = 0.08% ID g(-1)). IR-injected mice show localized uptake in the large intestine (5 h = 10.37% ID g(-1); 24 h = 0.42% ID g(-1)) with minimal uptake in other organs. Raman imaging of excised tissues correlate well with biodistribution data. These results suggest that the topical application of SERS nanoparticles in the mouse colon appears to minimize their systemic distribution, thus avoiding potential toxicity and supporting the clinical translation of Raman spectroscopy as an endoscopic imaging tool.
View details for DOI 10.1002/smll.201002317
View details for Web of Science ID 000294361200015
View details for PubMedID 21608124
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Fabrication of planar, layered nanoparticles using tri-layer resist templates
NANOTECHNOLOGY
2011; 22 (18)
Abstract
A simple and universal pathway to produce free multilayer synthetic nanoparticles is developed based on lithography, vapor phase deposition and a tri-layer resist lift-off and release process. The fabrication method presented in this work is ideal for production of a broad range of nanoparticles, either free in solution or still attached to an intact release layer, with unique magnetic, optical, radioactive, electronic and catalytic properties. Multi-modal capabilities are implicit in the layered architecture. As an example, directly fabricated magnetic nanoparticles are evaluated to illustrate the structural integrity of thin internal multilayers and the nanoparticle stability in aggressive biological environments, which is highly desired for biomedical applications.
View details for DOI 10.1088/0957-4484/22/18/185302
View details for Web of Science ID 000288653300005
View details for PubMedID 21415483
View details for PubMedCentralID PMC3143003
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Crater patterned 3-D proton conducting ceramic fuel cell architecture with ultra thin Y:BaZrO3 electrolyte
ELECTROCHEMISTRY COMMUNICATIONS
2011; 13 (5): 403-406
View details for DOI 10.1016/j.elecom.2011.02.004
View details for Web of Science ID 000290741500006
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The Fate and Toxicity of Raman-Active Silica-Gold Nanoparticles in Mice
SCIENCE TRANSLATIONAL MEDICINE
2011; 3 (79)
Abstract
Raman spectroscopy is an optical imaging method that is based on the Raman effect, the inelastic scattering of a photon when energy is absorbed from light by a surface. Although Raman spectroscopy is widely used for chemical and molecular analysis, its clinical application has been hindered by the inherently weak nature of the Raman effect. Raman-silica-gold-nanoparticles (R-Si-Au-NPs) overcome this limitation by producing larger Raman signals through surface-enhanced Raman scattering. Because we are developing these particles for use as targeted molecular imaging agents, we examined the acute toxicity and biodistribution of core polyethylene glycol (PEG)-ylated R-Si-Au-NPs after different routes of administration in mice. After intravenous administration, PEG-R-Si-Au-NPs were removed from the circulation by macrophages in the liver and spleen (that is, the reticuloendothelial system). At 24 hours, PEG-R-Si-Au-NPs elicited a mild inflammatory response and an increase in oxidative stress in the liver, which subsided by 2 weeks after administration. No evidence of significant toxicity was observed by measuring clinical, histological, biochemical, or cardiovascular parameters for 2 weeks. Because we are designing targeted PEG-R-Si-Au-NPs (for example, PEG-R-Si-Au-NPs labeled with an affibody that binds specifically to the epidermal growth factor receptor) to detect colorectal cancer after administration into the bowel lumen, we tested the toxicity of the core nanoparticle after administration per rectum. We observed no significant bowel or systemic toxicity, and no PEG-R-Si-Au-NPs were detected systemically. Although additional studies are required to investigate the long-term effects of PEG-R-Si-Au-NPs and their toxicity when carrying the targeting moiety, the results presented here support the idea that PEG-R-Si-Au-NPs can be safely used in living subjects, especially when administered rectally.
View details for DOI 10.1126/scitranslmed.3001963
View details for PubMedID 21508310
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Thermal conductivity anisotropy and grain structure in Ge2Sb2Te5 films
JOURNAL OF APPLIED PHYSICS
2011; 109 (8)
View details for DOI 10.1063/1.3573505
View details for Web of Science ID 000290047000229
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Atomic Layer Deposition of Lead Sulfide Quantum Dots on Nanowire Surfaces
NANO LETTERS
2011; 11 (3): 934-940
Abstract
Quantum dots provide unique advantages in the design of novel optoelectronic devices owing to the ability to tune their properties as a function of size. Here we demonstrate a new technique for fabrication of quantum dots during the nucleation stage of atomic layer deposition (ALD) of PbS. Islands with sub-10 nm diameters were observed during the initial ALD cycles by transmission electron microscopy, and in situ observations of the coalescence and sublimation behavior of these islands show the possibility of further modifying the size and density of dots by annealing. The ALD process can be used to cover high-aspect-ratio nanostructures, as demonstrated by the uniform coating of a Si nanowire array with a single layer of PbS quantum dots. Photoluminescence measurements on the quantum dot/nanowire composites show a blue shift when the number of ALD cycles is decreased, suggesting a route to fabricate unique three-dimensional nanostructured devices such as solar cells.
View details for DOI 10.1021/nl103001h
View details for Web of Science ID 000288061500003
View details for PubMedID 21319844
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Oxidative Stress Mediates the Effects of Raman-Active Gold Nanoparticles in Human Cells
SMALL
2011; 7 (1): 126-136
Abstract
Polyethylene glycol (PEG)ylated Raman-active gold nanoparticles (PEG-R-AuNPs) consist of an interchangeable Raman organic molecule layer held onto a gold nanocore by a silica shell. PEG-R-AuNPs have been shown preclinically to increase the sensitivity and specificity of Raman spectroscopy, with picomolar sensitivity and multiplexing capabilities. Although clinical trials are being designed to use functionalized PEG-R-AuNPs in various applications (e.g., to target dysplastic bowel lesions during colonoscopy), the effects of these nanoparticles on human cells remain unknown. The occurrence and mechanisms underlying any potential cytotoxicity induced by these nanoparticles (0-1000 PEG-R-AuNPs/cell) are investigated in immortalized human HeLa and HepG2 cell lines at several time points (0-48 h) after exposure. Using fluorometric assays, cell viability (MTT), reactive oxygen species (ROS) generation (dichlorofluorescein diacetate), protein oxidation (protein carbonyl content), and total cellular antioxidant concentrations the concentrations (metmyoblobin-induced oxidation of ABTS) are assessed. Analysis of lipid oxidation using an enzyme immunoassay (8-isoprostane concentrations), gene expression of antioxidant enzymes using quantitative reverse transcription polymerase chain reactions, and the intracellular location of PEG-R-AuNPs using transmission electron microscopy is also undertaken. PEG-R-AuNPs cause no cytotoxicity in either HeLa or HepG2 cells in the acute setting as ROS generation is balanced by antioxidant enzyme upregulation. Following prolonged exposures (48 h) at relatively high concentrations (1000 PEG-R-AuNPs/cell), nanoparticles are found within vesicles inside cells. Under these conditions, a minimal amount of cytotoxicity is seen in both cell lines owing to increases in cellular oxidative stress, most likely due to ROS overwhelming the antioxidant defenses. Evidence of oxidative stress-induced damage includes increased lipid and protein oxidation. Although further in vivo toxicity studies are necessary, these initial encouraging results show that PEG-R-AuNPs cause minimal toxicity in human cells in the acute setting, which bodes well for potential future applications of these nanoparticles in living subjects.
View details for DOI 10.1002/smll.201001466
View details for PubMedID 21104804
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Atomic layer deposition of CdxZn1-xS films
JOURNAL OF MATERIALS CHEMISTRY
2011; 21 (3): 743-751
View details for DOI 10.1039/c0jm02786c
View details for Web of Science ID 000285749900021
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Scanning Electron Microscopy and Surface Enhanced Raman Spectroscopy Correlation Studies of Functionalized Composite Organic-Inorganic SERS Nanoparticles on Cancer Cells
2011
View details for DOI 10.1557/opi.2011.664.
- Oxidative Stress Mediates the Effets of Raman Active Gold Nanoparticles in Human Cells Small 2011; 7: 126–136
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Crater Patterned 3-D Protonic Fuel Cell with Ultra Thin Y:BaZrO3 Ceramic Membrane
Electrochem. Comm.
2011; 5 (13): 403-406
View details for DOI 10.1016/j.elecom.2011.02.004.
- Correlative Microscopy of Tumor Vasculature 2011
- The Fate and Toxicity of Raman Active Silica-Gold Nanoparticles in Mice Sci Transl Med 2011; 3: 79ra33
- Effect of crystallinity on ionic conductivity of Y-doped Barium Zirconate Solid State Ionics 2011; 198 (1, 19): 39-46
- Proton Conduction in Epitaxial and Polycrystalline Yttrium-doped Barium Zirconate Thin Films 2011
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Scanning tunneling spectroscopy of lead sulfide quantum wells fabricated by atomic layer deposition
NANOTECHNOLOGY
2010; 21 (48)
Abstract
We report the use of scanning tunneling spectroscopy (STS) to investigate one-dimensional quantum confinement effects in lead sulfide (PbS) thin films. Specifically, quantum confinement effects on the band gap of PbS quantum wells were explored by controlling the PbS film thickness and potential barrier height. PbS quantum well structures with a thickness range of 1-20 nm were fabricated by atomic layer deposition (ALD). Two barrier materials were selected based on barrier height: aluminum oxide as a high barrier material and zinc oxide as a low barrier material. Band gap measurements were carried out by STS, and an effective mass theory was developed to compare the experimental results. Our results show that the band gap of PbS thin films increased as the film thickness decreased, and the barrier height increased from 0.45 to 2.19 eV.
View details for DOI 10.1088/0957-4484/21/48/485402
View details for Web of Science ID 000284053500011
View details for PubMedID 21063050
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Laser-Synthesized Epitaxial Graphene
ACS NANO
2010; 4 (12): 7524-7530
Abstract
Owing to its unique electronic properties, graphene has recently attracted wide attention in both the condensed matter physics and microelectronic device communities. Despite intense interest in this material, an industrially scalable graphene synthesis process remains elusive. Here, we demonstrate a high-throughput, low-temperature, spatially controlled and scalable epitaxial graphene (EG) synthesis technique based on laser-induced surface decomposition of the Si-rich face of a SiC single-crystal. We confirm the formation of EG on SiC as a result of excimer laser irradiation by using reflection high-energy electron diffraction (RHEED), Raman spectroscopy, synchrotron-based X-ray diffraction, transmission electron microscopy (TEM), and scanning tunneling microscopy (STM). Laser fluence controls the thickness of the graphene film down to a single monolayer. Laser-synthesized graphene does not display some of the structural characteristics observed in EG grown by conventional thermal decomposition on SiC (0001), such as Bernal stacking and surface reconstruction of the underlying SiC surface.
View details for DOI 10.1021/nn101796e
View details for PubMedID 21121692
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Atomic Layer Deposition of CdS Films
CHEMISTRY OF MATERIALS
2010; 22 (16): 4669-4678
View details for DOI 10.1021/cm100874f
View details for Web of Science ID 000280855100021
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Atomic layer deposition of ZnS via in situ production of H2S
THIN SOLID FILMS
2010; 518 (19): 5400-5408
View details for DOI 10.1016/j.tsf.2010.03.074
View details for Web of Science ID 000279885700009
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Structural and magnetic characterizations of high moment synthetic antiferromagnetic nanoparticles fabricated using self-assembled stamps
11th Joint MMM-Intermag Conference
AMER INST PHYSICS. 2010
View details for DOI 10.1063/1.3358067
View details for Web of Science ID 000277834300225
- Utilizing Scanning Transmission Electron Microscopy to Locate and Image Raman Active Gold Core Nanoparticles in Mouse Tissue 2010
- TEM Study on PbS Quantum Dots Made by Atomic Layer Deposition and Their Behavior Under E-beam Irradiation 2010
- Utilizing Scanning Transmission Electron Microscopy to Locate and Image Raman Active Gold Core Nanoparticles in Mouse Tissue 2010
- Nanostructural correlation between Co magnetic layer and its Ru seed layer in a PMR medium 2010
- Structural and Magnetic Characterization of High Moment Synthetic Antiferromagnetic Nanoparticles Fabricated Using Self-Assembled Stamps J. Appl Phys. 2010; 107: 09B522 1-3
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Organic-Inorganic Particles as Labels to Trace Biological Signaling Pathways
2010
View details for DOI 10.1017/S143192761005899X.
- Developing Remote Microscopy at a University User Facility 2010
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Electron Energy-Loss Spectrometry (EELS) and Energy-Filtered TEM (EFTEM) Analyses of Organic-Inorganic Nanoparticles
CAMBRIDGE UNIV PRESS. 2009: 432–433
View details for DOI 10.1017/S1431927609092964
View details for Web of Science ID 000208119100214
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In Situ and High Resolution TEM Studies of Nano-scale Materials
CAMBRIDGE UNIV PRESS. 2009: 1200–1201
View details for DOI 10.1017/S1431927609097554
View details for Web of Science ID 000208119100591
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Formation and properties of magnetic chains for 100nm nanoparticles used in separations of molecules and cells
7th International Conference on Scientific and Clinical Applications of Magnetic Carriers
ELSEVIER SCIENCE BV. 2009: 1452–58
Abstract
Optical observations of 100 nm metallic magnetic nanoparticles are used to study their magnetic field induced self assembly. Chains with lengths of tens of microns are observed to form within minutes at nanoparticle concentrations of 10(10) per mL. Chain rotation and magnetophoresis are readily observed, and SEM reveals that long chains are not simple single particle filaments. Similar chains are detected for several 100 nm commercial bio-separation nanoparticles. We demonstrate the staged magnetic condensation of different types of nanoparticles into composite structures and show that magnetic chains bind to immunomagnetically labeled cells, serving as temporary handles which allow novel magnetic cell manipulations.
View details for DOI 10.1016/j.jmmm.2009.02.066
View details for Web of Science ID 000265278000028
View details for PubMedCentralID PMC2757286
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Formation and properties of magnetic chains for 100 nm nanoparticles used in separations of molecules and cells.
Journal of magnetism and magnetic materials
2009; 321 (10): 1452-1458
Abstract
Optical observations of 100 nm metallic magnetic nanoparticles are used to study their magnetic field induced self assembly. Chains with lengths of tens of microns are observed to form within minutes at nanoparticle concentrations of 10(10) per mL. Chain rotation and magnetophoresis are readily observed, and SEM reveals that long chains are not simple single particle filaments. Similar chains are detected for several 100 nm commercial bio-separation nanoparticles. We demonstrate the staged magnetic condensation of different types of nanoparticles into composite structures and show that magnetic chains bind to immunomagnetically labeled cells, serving as temporary handles which allow novel magnetic cell manipulations.
View details for DOI 10.1016/j.jmmm.2009.02.066
View details for PubMedID 20161001
View details for PubMedCentralID PMC2757286
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A Novel Method for Detection of Phosphorylation in Single Cells by Surface Enhanced Raman Scattering (SERS) using Composite Organic-Inorganic Nanoparticles (COINs)
PLOS ONE
2009; 4 (4)
Abstract
Detection of single cell epitopes has been a mainstay of immunophenotyping for over three decades, primarily using fluorescence techniques for quantitation. Fluorescence has broad overlapping spectra, limiting multiplexing abilities.To expand upon current detection systems, we developed a novel method for multi-color immuno-detection in single cells using "Composite Organic-Inorganic Nanoparticles" (COINs) Raman nanoparticles. COINs are Surface-Enhanced Raman Scattering (SERS) nanoparticles, with unique Raman spectra. To measure Raman spectra in single cells, we constructed an automated, compact, low noise and sensitive Raman microscopy device (Integrated Raman BioAnalyzer). Using this technology, we detected proteins expressed on the surface in single cells that distinguish T-cells among human blood cells. Finally, we measured intracellular phosphorylation of Stat1 (Y701) and Stat6 (Y641), with results comparable to flow cytometry.Thus, we have demonstrated the practicality of applying COIN nanoparticles for measuring intracellular phosphorylation, offering new possibilities to expand on the current fluorescent technology used for immunoassays in single cells.
View details for DOI 10.1371/journal.pone.0005206
View details for Web of Science ID 000265510400006
View details for PubMedID 19367337
View details for PubMedCentralID PMC2666268
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Synthetic antiferromagnetic nanoparticles with tunable susceptibilities
53rd Annual Conference on Magnetism and Magnetic Materials
AMER INST PHYSICS. 2009
Abstract
High-moment monodisperse disk-shaped Co-Fe magnetic nanoparticles, stable in aqueous solution, were physically fabricated by using nanoimprinted templates and vacuum deposition techniques. These multilayer synthetic antiferromagnetic nanoparticles exhibit nearly zero magnetic remanence and coercivity, and susceptibilities which can be tuned by exploiting interlayer magnetic interactions. In addition, a low cost method of scaling up the production of sub-100 nm synthetic antiferromagnetic nanoparticles is demonstrated.
View details for DOI 10.1063/1.3072028
View details for Web of Science ID 000266633500313
View details for PubMedCentralID PMC2685219
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Particle Size, Surface Coating, and PEGylation Influence the Biodistribution of Quantum Dots in Living Mice
SMALL
2009; 5 (1): 126-134
Abstract
This study evaluates the influence of particle size, PEGylation, and surface coating on the quantitative biodistribution of near-infrared-emitting quantum dots (QDs) in mice. Polymer- or peptide-coated 64Cu-labeled QDs 2 or 12 nm in diameter, with or without polyethylene glycol (PEG) of molecular weight 2000, are studied by serial micropositron emission tomography imaging and region-of-interest analysis, as well as transmission electron microscopy and inductively coupled plasma mass spectrometry. PEGylation and peptide coating slow QD uptake into the organs of the reticuloendothelial system (RES), liver and spleen, by a factor of 6-9 and 2-3, respectively. Small particles are in part renally excreted. Peptide-coated particles are cleared from liver faster than physical decay alone would suggest. Renal excretion of small QDs and slowing of RES clearance by PEGylation or peptide surface coating are encouraging steps toward the use of modified QDs for imaging living subjects.
View details for DOI 10.1002/smll.200800003
View details for Web of Science ID 000262895300019
View details for PubMedID 19051182
View details for PubMedCentralID PMC3084659
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Real-time visualization of RGD-quantum dot binding in tumor neovasculature using intravital microscopy in multiple living mouse models
Conference on Colloidal Quantum Dots for Biomedical Applications IV
SPIE-INT SOC OPTICAL ENGINEERING. 2009
View details for DOI 10.1117/12.809578
View details for Web of Science ID 000285710600021
- No Titan, No Excuse’ (T.J. Konno, 1 April 2008) A Report on an International Workshop on Remote Electron Microscopy for In Situ Studies Acta Microscopica 2009; 1 (18): 33–38
- Direct Microscale Visualization of Targeted Quantum Dot Binding in Multiple Tumor Models of Living Mice using Intravital Microscopy 2009
- Formation and properties of magnetic chains for 100 nm nanoparticles used in separations of molecules and cells J. Magn. Magn. Mat. 2009; 321: 1452–1458
- Electron Microscopy Characterization of Gold-Silica Core-Shell Nanoparticle Raman Labels (Nanoplex™ Biotags) and their Conjugation to Cells 2009
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"NO TITAN, NO EXCUSE" (T. J. KONNO, 1 APRIL 2008) A REPORT ON AN INTERNATIONAL WORKSHOP ON REMOTE ELECTRON MICROSCOPY FOR IN SITU STUDIES
ACTA MICROSCOPICA
2009; 18 (1): 33-38
View details for Web of Science ID 000276809600004
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Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells
ULTRAMICROSCOPY
2008; 109 (1): 111-121
Abstract
We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic nanoparticle (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet scanning electron microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both cases, the backscattered electron (BSE) detector was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution transmission electron microscopy (TEM) images and scanning Auger electron spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens.
View details for DOI 10.1016/j.ultramic.2008.09.004
View details for Web of Science ID 000261750500016
View details for PubMedID 18995965
View details for PubMedCentralID PMC2650478
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Multiplex Detection of Protease Activity with Quantum Dot Nanosensors Prepared by Intein-Mediated Specific Bioconjugation
ANALYTICAL CHEMISTRY
2008; 80 (22): 8649-8655
Abstract
We report here a protease sensing nanoplatform based on semiconductor nanocrystals or quantum dots (QDs) and bioluminescence resonance energy transfer (QD-BRET) to detect the protease activity in complex biological samples. These nanosensors consist of bioluminescent proteins as the BRET donor, quantum dots as the BRET acceptor, and protease substrates sandwiched between the two as a sensing group. An intein-mediated conjugation strategy was developed for site-specific conjugation of proteins to QDs in preparing these QD nanosensors. In this traceless ligation, the intein itself is spliced out and excluded from the final conjugation product. With this method, we have synthesized a series of QD nanosensors for highly sensitive detection of an important class of protease matrix metalloproteinase (MMP) activity. We demonstrated that these nanosensors can detect the MMP activity in buffers and in mouse serum with the sensitivity to a few nanograms per milliliter and secreted proteases by tumor cells. The suitability of these nanosensors for a multiplex protease assay has also been shown.
View details for DOI 10.1021/ac801562f
View details for Web of Science ID 000260910900039
View details for PubMedID 18922019
View details for PubMedCentralID PMC2677517
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TEM analyses of synthetic anti-ferromagnetic (SAF) nanoparticles fabricated using different release layers
11th Conference on Frontiers of Electron Microscopy in Materials Science
ELSEVIER SCIENCE BV. 2008: 1490–94
Abstract
This paper investigates the structural characteristics of templated synthetic anti-ferromagnetic (SAF) magnetic nanoparticles fabricated on two different release layers. When copper was used as the latter, the layered structure of the SAFs was found to be disrupted with wavy multi-layers due to the formation of copper grains from the release layer. By introducing oxygen into the copper release layer before the deposition of the film, the topography of the oxidized copper grains was effectively controlled. This led to the fabrication of SAF nanoparticles with flat multi-layers.
View details for DOI 10.1016/j.ultramic.2008.03.012
View details for Web of Science ID 000260518200014
View details for PubMedID 18672328
View details for PubMedCentralID PMC2582063
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Real-time intravital imaging of RGD-quantum dot binding to luminal endothelium in mouse tumor neovasculature
NANO LETTERS
2008; 8 (9): 2599-2606
Abstract
Nanoscale materials have increasingly become subject to intense investigation for use in cancer diagnosis and therapy. However, there is a fundamental dearth in cellular-level understanding of how nanoparticles interact within the tumor environment in living subjects. Adopting quantum dots (qdots) for their excellent brightness, photostability, monodispersity, and fluorescent yield, we link arginine-glycine-aspartic acid (RGD) peptides to target qdots specifically to newly formed/forming blood vessels expressing alpha vbeta 3 integrins. Using this model nanoparticle system, we exploit intravital microscopy with subcellular ( approximately 0.5 microm) resolution to directly observe and record, for the first time, the binding of nanoparticle conjugates to tumor blood vessels in living subjects. This generalizable method enabled us to show that in this model qdots do not extravasate and, unexpectedly, that they only bind as aggregates rather than individually. This level of understanding is critical on the path toward ensuring regulatory approval of nanoparticles in humans for disease diagnostics and therapeutics. Equally vital, the work provides a platform by which to design and optimize molecularly targeted nanoparticles including quantum dots for applications in living subjects.
View details for DOI 10.1021/nl80141f
View details for Web of Science ID 000259140200001
View details for PubMedID 18386933
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Improved QD-BRET conjugates for detection and imaging
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
2008; 372 (3): 388-394
Abstract
Self-illuminating quantum dots, also known as QD-BRET conjugates, are a new class of quantum dot bioconjugates which do not need external light for excitation. Instead, light emission relies on the bioluminescence resonance energy transfer from the attached Renilla luciferase enzyme, which emits light upon the oxidation of its substrate. QD-BRET combines the advantages of the QDs (such as superior brightness and photostability, tunable emission, multiplexing) as well as the high sensitivity of bioluminescence imaging, thus holding the promise for improved deep tissue in vivo imaging. Although studies have demonstrated the superior sensitivity and deep tissue imaging potential, the stability of the QD-BRET conjugates in biological environment needs to be improved for long-term imaging studies such as in vivo cell tracking. In this study, we seek to improve the stability of QD-BRET probes through polymeric encapsulation with a polyacrylamide gel. Results show that encapsulation caused some activity loss, but significantly improved both the in vitro serum stability and in vivo stability when subcutaneously injected into the animal. Stable QD-BRET probes should further facilitate their applications for both in vitro testing as well as in vivo cell tracking studies.
View details for DOI 10.1016/j.bbrc.2008.04.159
View details for Web of Science ID 000256941300002
View details for PubMedID 18468518
View details for PubMedCentralID PMC2529157
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Synthesis and characterization of PVP-coated large core iron oxide nanoparticles as an MRI contrast agent
NANOTECHNOLOGY
2008; 19 (16)
Abstract
The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI) contrast agent. The PVP-IO nanoparticles were synthesized by a thermal decomposition method and characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and a superconducting quantum interface device (SQUID). The core size of the particles is about 8-10 nm and the overall size is around 20-30 nm. The measured r(2) (reciprocal of T(2) relaxation time) and r2∗ (reciprocal of T2∗ relaxation time) are 141.2 and 338.1 (s mM)(-1), respectively. The particles are highly soluble and stable in various buffers and in serum. The macrophage uptake of PVP-IO is comparable to that of Feridex as measured by a Prussian blue iron stain and phantom study. The signal intensity of a rabbit liver was effectively reduced after intravenous administration of PVP-IO. Therefore PVP-IO nanoparticles are potentially useful for T(2)-weighted MR imaging.
View details for DOI 10.1088/0957-4484/19/16/165101
View details for Web of Science ID 000254174800001
View details for PubMedCentralID PMC3050625
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High-moment antiferromagnetic nanoparticles with tunable magnetic properties
ADVANCED MATERIALS
2008; 20 (8): 1479-?
View details for DOI 10.1002/adma.200703077
View details for Web of Science ID 000255694200015
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Synthesis and characterization of PVP-coated large core iron oxide nanoparticles as an MRI contrast agent.
Nanotechnology
2008; 19 (16): 165101
Abstract
The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI) contrast agent. The PVP-IO nanoparticles were synthesized by a thermal decomposition method and characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and a superconducting quantum interface device (SQUID). The core size of the particles is about 8-10 nm and the overall size is around 20-30 nm. The measured r(2) (reciprocal of T(2) relaxation time) and r2∗ (reciprocal of T2∗ relaxation time) are 141.2 and 338.1 (s mM)(-1), respectively. The particles are highly soluble and stable in various buffers and in serum. The macrophage uptake of PVP-IO is comparable to that of Feridex as measured by a Prussian blue iron stain and phantom study. The signal intensity of a rabbit liver was effectively reduced after intravenous administration of PVP-IO. Therefore PVP-IO nanoparticles are potentially useful for T(2)-weighted MR imaging.
View details for DOI 10.1088/0957-4484/19/16/165101
View details for PubMedID 21394237
View details for PubMedCentralID PMC3050625
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Preparation, structural and magnetic characterization of synthetic anti-ferromagnetic (SAF) nanoparticles
PHILOSOPHICAL MAGAZINE
2008; 88 (36): 4225-4241
View details for DOI 10.1080/14786430802585133
View details for Web of Science ID 000261804200002
- Electron Microscopy Characterization of Composite Organic-Inorganic Nanoparticles (COINs) as Raman Labels for Extra-Cellular Analyses Microsc. Microanal. 2008; 14: 670CD
- Electron Microscopy Characterization of Composite Organic-Inorganic Nanoparticles (COINs) as Raman Labels for Extra-Cellular Analyses 2008
- Real-Time Intravital Imaging of RGD−Quantum Dot Binding to Luminal Endothelium in Mouse Tumor Neovasculature Nano Letters 2008; 9 (8): 2599-2606
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Analytical TEM examinations of CoPt-TiO2 perpendicular magnetic recording media
MICROSCOPY AND MICROANALYSIS
2007; 13 (2): 70-79
Abstract
For this analytical TEM study, nonmagnetic oxygen-rich boundaries were introduced into Co-Pt-alloy perpendicular recording media by cosputtering Co and Pt with TiO2. Increasing the TiO2 content resulted in changes to the microstructure and elemental distribution within grains and boundaries in these films. EFTEM imaging was used to generate composition maps spanning many tens of grains, thereby giving an overall depiction of the changes in elemental distribution occurring with increasing TiO2 content. Comparing EFTEM with spectrum-imaging maps created by high-resolution STEM with EDXS and EELS enabled both corroboration of EFTEM results and quantification of the chemical composition within individual grain boundary areas. The difficulty of interpreting data from EDXS for these extremely thin films is discussed. Increasing the TiO2 content of the media was found to create more uniformly wide Ti- and O-rich grain boundaries as well as Ti- and O-rich regions within grains.
View details for DOI 10.1017/S14319276070213
View details for Web of Science ID 000245662200001
View details for PubMedID 17367546
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Orientation relationship in diamond and silicon carbide composites
DIAMOND AND RELATED MATERIALS
2007; 16 (3): 562-565
View details for DOI 10.1016/j.diamond.2006.11.050
View details for Web of Science ID 000244827100024
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Microstructure and exchange coupling of segregated oxide perpendicular recording media
17th Annual Magnetic Recording Conference (TMRC 2006)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 2007: 639–44
View details for DOI 10.1109/TMAG.2006.888208
View details for Web of Science ID 000244011300011
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Characterization of magnetic nano-particles by high resolution TEM methods
CAMBRIDGE UNIV PRESS. 2007: 66–67
View details for DOI 10.1017/S1431927607079238
View details for Web of Science ID 000258691300033
- TEM Studies of Iron Oxide Nanoparticles for Cell Labeling and Magnetic Separation 2007
- Grain Size Distribution in CoCrPtO-based Perpendicular Magnetic Recording Media 2007
- Characterization of Magnetic Nanoparticles by High Resolution TEM Methods 2007
- TEM Observations of Bio-conjugated Streptavidin-Gold Particles 2007
- TEM Studies of Synthetic Anti-ferromagnetic (SAF) Nanoparticles 2007
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Composition mapping of Co-Pt-Ti-O perpendicular magnetic recording media by simultaneous EDS and EELS spectrum imaging
CAMBRIDGE UNIV PRESS. 2007: 158–159
View details for DOI 10.1017/S1431927607078385
View details for Web of Science ID 000258691300079
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Effect of magnetic recording layer thickness on media performance in CoCrPt-oxide perpendicular media
41st IEEE International Magnetics Conference (Intermag 2006)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 2006: 2330–32
View details for DOI 10.1109/TMAG.2006.878697
View details for Web of Science ID 000240888700027
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FIB and TEM studies of interface structure in diamond-SiC composites
10th Meeting on Frontiers of Electron Microscopy in Materials Science
SPRINGER. 2006: 4611–16
View details for DOI 10.1007/s10853-006-0249-7
View details for Web of Science ID 000239720900026
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Observation of the effect of grain orientation on chromium segregation in longitudinal magnetic media
JOURNAL OF APPLIED PHYSICS
2006; 99 (3)
View details for DOI 10.1063/1.2169873
View details for Web of Science ID 000235341000048
- Information Storage Technology: The Role of the TEM 2006
- TEM Studies of Reactions in Thin Films and their Interfaces 2006
- Characterization of AuFe-C Core-shell Nanoparticles 2006
- FIB and TEM Studies of Interface Structure in Diamond-SiC Composites 2006
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Ru/Ru-oxide interlayers for CoCrPtO perpendicular recording media
International Magnetics Conference (Intermag 2005)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 2005: 3193–95
View details for DOI 10.1109/TMAG.2005.855281
View details for Web of Science ID 000232679700204
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High-Resolution Analytical TEM and Energy-Filtered Imaging of CoPt-Oxide Perpendicular Magnetic Recording Media.
Microscopy and microanalysis
2005; 11: 1806-1807
Abstract
Extended abstract of a paper presented at Microscopy and Microanalysis 2005 in Honolulu, Hawaii, USA, July 31--August 4, 2005.
View details for DOI 10.1017/S1431927605502186
View details for PubMedID 24017771
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Crystallization behaviour of ALD-Ta2O5 thin films: the application of in-situ TEM
PHILOSOPHICAL MAGAZINE
2005; 85 (18): 2049-2063
View details for DOI 10.1080/147864305000365465
View details for Web of Science ID 000230456100008
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Crystallization and anisotropic dielectric properties of tantalum oxide thin films
JOURNAL OF CERAMIC PROCESSING RESEARCH
2005; 6 (1): 17-19
View details for Web of Science ID 000228339100003
- HRTEM and Nano-probe EDS Studies on the Microstructure of CoCrPtO Perpendicular Recording Media with Ru/Ru-oxide Interlayers 2005
- High-Resolution Analytical TEM and Energy-Filtered Imaging of CoPt-Oxide Perpendicular Magnetic Recording Media 2005
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Application of in situ HREM to study crystallization in materials
6th Conference of the Yugoslav-Materials-Research-Society
TRANS TECH PUBLICATIONS LTD. 2005: 7–11
View details for Web of Science ID 000230985800002
- Application of In Situ HREM to Study Crystallization in Materials Materials Science Forum 2005; 494: 7-12
- Crystallization Behavior of ALD-Ta2O5 Thin Films: An Application of In-situ TEM Philos. Mag. 2005; 18 (85): 2049-2063
- Synthesis and Characterization of Fe-C Core-shell Nanoparticles 2005
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Investigation of the chemical state of ultrathin Hf-Al-O films during high temperature annealing
SURFACE SCIENCE
2004; 554 (1): L75-L80
View details for DOI 10.1016/j.susc.2004.01.058
View details for Web of Science ID 000220419700001
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Change in the chemical state and thermal stability of HfO2 by the incorporation of Al2O3
APPLIED PHYSICS LETTERS
2004; 84 (4): 571-573
View details for DOI 10.1063/1.1633976
View details for Web of Science ID 000188316500039
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Recent developments in nano-characterization of materials
JOURNAL OF CERAMIC PROCESSING RESEARCH
2004; 5 (1): 5-9
View details for Web of Science ID 000220751400002
- High Resolution and Analytical TEM of Cr Grain Boundary Segregation in Co-alloy Longitudinal Hard Disk Magnetic Recording Media 2004
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Carbide evolution in temper embrittled NiCrMoV bainitic steel
STEEL RESEARCH INTERNATIONAL
2004; 75 (1): 47-54
View details for Web of Science ID 000188261600008
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Thermal stability of epitaxial Pt films on Y2O3 in a metal-oxide-Si structure
APPLIED PHYSICS LETTERS
2003; 83 (23): 4758-4760
View details for DOI 10.1063/1.1632541
View details for Web of Science ID 000186970200024
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Transmission electron microscopy analysis of computer hard disc, magnetic thin films
11th International Conference on Electron Microscopy of Solids
ELSEVIER SCIENCE SA. 2003: 241–43
View details for DOI 10.1016/S0254-0584(02)00559-X
View details for Web of Science ID 000184572200012
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Characterization for crystallization of SrBi2Nb2O9 thin films on Si substrates
11th Seoul International Symposium on the Physics of Semiconductors and Applications
KOREAN PHYSICAL SOC. 2003: S450–S453
View details for Web of Science ID 000181337500084
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The effects of slider material on the gasification of carbon
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
2002; 124 (4): 771-774
View details for DOI 10.1115/1.1467613
View details for Web of Science ID 000178565200013
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In situ TEM studies of metal-carbon reactions
MICROSCOPY AND MICROANALYSIS
2002; 8 (4): 288-304
Abstract
The reactions which occur between amorphous carbon and a number of first transition metals (Ti, Cr, Fe, Co, Ni, and Cu) have been studied by transmission electron microscopy (TEM). The materials are in thin-film form with the metal layer sandwiched between thicker carbon layers. In four cases, the predominant reaction is the graphitization of the amorphous carbon, at temperatures well below 800 degrees C. This is brought about by the elements themselves in the case of Co and Ni, and by metastable carbides in the case of Fe (Fe3C) and Cr (Cr3C2-x). The Ti-C and Cu-C systems do not exhibit graphitization. For the former, only TiC is produced up to 1000 degrees C, while the carbon does not react at all with copper. In situ TEM studies show the mechanism to be of the dissolution-precipitation type, which is equivalent to the metal-mediated crystallization process for amorphous silicon and germanium. The heat of graphitization is found to be 18-19 kcal/mol-C by differential scanning calorimetry.
View details for DOI 10.1017/S1431927602020226
View details for Web of Science ID 000179056000007
View details for PubMedID 12533226
- In Situ HREM of Crystallization Reactions 2002
- In-Situ Heating Study of Materials 2002
- Failure Analysis of Ferroelectric RAM Device by Transmission Electron Microscopy 2002
- Reactions in Metal-Carbon Systems 2002
- TEM Microstructure Studies of Thin Film Magnetic Recording Media 2002
- Grain Size Relationship Between the Magnetic Layer and the Underlayer in CoCrPtTa Recording Media 2001
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Microstructural characterization of longitudinal magnetic recording media
Symposium on Advances in Materials Problem Solving with the Electron Microscope held at the 1999 MRS Fall Meeting
MATERIALS RESEARCH SOCIETY. 2001: 3–12
View details for Web of Science ID 000172649100001
- Transmission Electron Microscopy of Computer Hard Disc, Magnetic Thin Films edited by Kawaii, T. 2001
- Quantitative EFTEM of Cr Grain Boundary Segregation in CoCrTa 2001
- Microstructural Characterization of Longitudinal Magnetic Recording Media 2001
- In Situ Transmission Electron Microscopy of Materials edited by Chen, L., J. 2001
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Grain size analysis of longitudinal thin film media
44th Annual Conference on Magnetism and Magnetic Materials
AMER INST PHYSICS. 2000: 5687–89
View details for Web of Science ID 000086727200329
- In Situ HREM of Interface Reactions edited by Yoshihara, K. 2000
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Thermal stability of a Cu/Ta multilayer: An intriguing interfacial reaction
Acta Materialia Workshop on Materials Science and Mechanics of Interfaces
PERGAMON-ELSEVIER SCIENCE LTD. 1999: 3965–75
View details for Web of Science ID 000084063800004
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A study of the failure mechanism of a titanium nitride diffusion barrier
JOURNAL OF APPLIED PHYSICS
1999; 86 (6): 3096-3103
View details for Web of Science ID 000082232400024
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Study of DC plasma oxidized Al2O3 barriers in spin dependent tunneling junctions using high resolution transmission electron microscopy
1999 International Magnetics Conference (INTERMAG 99)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1999: 2922–24
View details for Web of Science ID 000083151100223
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Case study of media noise mechanisms in longitudinal recording
1999 International Magnetics Conference (INTERMAG 99)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1999: 2730–32
View details for Web of Science ID 000083151100165
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Solid-state amorphization at tetragonal-Ta/Cu interfaces
APPLIED PHYSICS LETTERS
1999; 75 (7): 935-937
View details for Web of Science ID 000081928700018
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Wear-induced modifications of amorphous carbon in the presence of magnetic media
43rd Annual Conference on Magnetism and Magnetic Materials
AMER INST PHYSICS. 1999: 5597–99
View details for Web of Science ID 000079853500105
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Growth and characterization of epitaxial NiMnSb/PtMnSb C1(b) Heusler alloy superlattices
JOURNAL OF MATERIALS RESEARCH
1999; 14 (4): 1560-1569
View details for Web of Science ID 000082550400055
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Crystallization of amorphous carbon thin films in the presence of magnetic media
JOURNAL OF APPLIED PHYSICS
1999; 85 (3): 1508-1513
View details for Web of Science ID 000078137100031
- Thermal Stability of a Cu/Ta Multilayer: an Intriguing Interfacial Reaction Acta Mater. 1999; 15/16 (47): 3965-3975
- Thermal Stability of the Copper/Tantalum Interfaces in Advanced Microelectronic Metallization 1999
- Growth and Characterization of Epitaxial NiMnSb/PtMnSb C1b Heusler Alloy Superlattices J. Mater. Res. 1999; 4 (14): 1560-1569
- Magnetic Imaging of Recording Media 1999
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Kinetic analysis of the C49-to-C54 phase transformation in TiSi2 thin films by in situ observation
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS
1998; 37 (8): 4284-4287
View details for Web of Science ID 000076313100010
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Effects of ultra-high vacuum on crystallographic, recording and magnetic properties of thin film media
7th Joint MMM-Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1998: 1576–78
View details for Web of Science ID 000074852300246
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Chromium segregation in CoCrTa/Cr and CoCrPt/Cr thin films for longitudinal recording media
7th Joint MMM-Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1998: 1564–66
View details for Web of Science ID 000074852300242
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Interfacial reaction in the poly-Si/Ta2O5/TiN capacitor system
JOURNAL OF APPLIED PHYSICS
1998; 83 (1): 139-144
View details for Web of Science ID 000071320400021
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Chromium distribution in CoCrTa/Cr longitudinal recording media
Symposium L on Materials for High-Density Magnetic Recording / Symposium M on Integrated Magneto-Optics at the MRS Spring Meeting
MATERIALS RESEARCH SOCIETY. 1998: 211–216
View details for Web of Science ID 000076893400032
- Roughness Measurements of Thin SiO2 and poly-Si Interfaces Using High Resolution Cross-Sectional TEM 1998
- Chromium Distrubution in CoCrTa/Cr Longitudinal Recording Media 1998
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Evidence of heteroepitaxial growth of copper on beta-tantalum
APPLIED PHYSICS LETTERS
1997; 71 (21): 3069-3071
View details for Web of Science ID A1997YG83400013
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Wear effects on microstructural features of amorphous-carbon thin films
24th International Conference on Metallurgical Coatings and Thin Films (ICMCTF 97)
ELSEVIER SCIENCE SA. 1997: 549–54
View details for Web of Science ID 000070981000094
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Magnetic clusters, intergranular exchange interaction and their microstructural basis in thin film longitudinal media
35th Annual IEEE International Magnetics Conference (INTERMAG 97)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1997: 4074–76
View details for Web of Science ID A1997XW56500190
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Nanoroughness effect on Cr growth mechanism
41st Annual Conference on Magnetism and Magnetic Materials
AMER INST PHYSICS. 1997: 3943–45
View details for Web of Science ID A1997WV53600079
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Evolution of bicrystal media development
7th Annual Magnetic Recording Conference (TMRC) on Media
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1997: 885–90
View details for Web of Science ID A1997WF01300031
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Roughness measurements of thin SiO2 and poly-Si interfaces using high resolution cross-sectional TEM
Symposium on Silicon Nitride and Silicon Dioxide Thin Insulating Films
ELECTROCHEMICAL SOCIETY INC. 1997: 232–39
View details for Web of Science ID A1997BJ51X00019
- Evidence of Heteroepitaxial Growth of Copper on β-Tantalum Appl. Phys. Lett. 1997; 71: 3069-3071
- Evolution of Bicrystal Media IEEE Trans. Magn. 1997; 33: 885-890
- Applications of TEM for Analysis of Local Failures Occurring During Si Metallization Process 1997
- Micromagnetic and Microstructure-Property Relationships in Magnetic Recording Media 1997
- Wear Effects on the Microstructural Features of Amorphous Carbon Thin Film Surf. Coat. Tech. 1997; 94-95: 549-554
- Structure-Property Relationships in Sputtered Magneto-optic Multilayers 1997
- Nano-roughness Effect on Cr Growth Mechanism J. Appl. Phys. 1997; 8 (81): 3943-3946
- Diffusion Barrier Stability in ULSI Applications 1997
- In Situ HREM of Reactions at Interfaces 1997
- Characterization of Ta as an underlayer for Cu Interconnects 1997
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Growth of alpha' nitrogen martensite and Fe16N2 films using (001)silicon substrates
1996 IEEE International Magnetics Conference (INTERMAG 96)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1996: 3503–5
View details for Web of Science ID A1996VM25800047
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Microstructure/magnetic property relationships in CoCrPt magnetic thin films
1996 IEEE International Magnetics Conference (INTERMAG 96)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1996: 3587–89
View details for Web of Science ID A1996VM25800074
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Thin film media with and without bicrystal cluster structure on glass ceramic substrates
1996 IEEE International Magnetics Conference (INTERMAG 96)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1996: 3599–3601
View details for Web of Science ID A1996VM25800078
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Measurements of crystalline anisotropy on longitudinal media
1996 IEEE International Magnetics Conference (INTERMAG 96)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1996: 4902–4
View details for Web of Science ID A1996VM25900198
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Lorentz transmission electron microscopy study of micromagnetic structures in real computer hard disks
1996 IEEE International Magnetics Conference (INTERMAG 96)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1996: 4130–32
View details for Web of Science ID A1996VM25800245
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Analyses of stacking fault density in Co-alloy thin films by high-resolution transmission electron microscopy
1996 IEEE International Magnetics Conference (INTERMAG 96)
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1996: 3605–7
View details for Web of Science ID A1996VM25800080
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Atomically flat, ultra thin-SiO2/Si(001) interface formation by UHV healing
13th International Vacuum Congress/9th International Conference on Solid Surfaces (IVC-13/ICSS-9)
ELSEVIER SCIENCE BV. 1996: 425–430
View details for Web of Science ID A1996VD64000089
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Structural comparisons of ion beam and de magnetron sputtered spin valves by high-resolution transmission electron microscopy
40th Annual Conference on Magnetism and Magnetic Materials
AMER INST PHYSICS. 1996: 6393–95
View details for Web of Science ID A1996UG87800298
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In situ observation of the C49-to-C54 phase transformation in TiSi2 thin films by transmission electron microscopy
JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS
1996; 35 (4B): L479-L481
View details for Web of Science ID A1996UM42200006
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Anomalous moment and anisotropy behavior in Fe3O4 films
PHYSICAL REVIEW B
1996; 53 (14): 9175-9187
View details for Web of Science ID A1996UF06400055
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Magnetic and structural characteristics of sputtered barium ferrite thin films
6th International Conference on Magnetic Recording Media
ELSEVIER SCIENCE BV. 1996: 157–60
View details for Web of Science ID A1996UU48500047
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As-deposited crystalline barium ferrite thin film media for longitudinal recording
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
1996; 153 (1-2): 246-254
View details for Web of Science ID A1996TY73300031
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Effects of Pt addition on the magnetic and crystallographic properties of Co-Cr-Pt thin-film media
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
1996; 152 (1-2): 265-273
View details for Web of Science ID A1996TT38200039
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In situ atomic resolution electron microscopy of metal-mediated crystallization of semiconductors
2nd International Conference on Grain Growth in Polycrystalline Materials
TRANS TECH PUBLICATIONS LTD. 1996: 749–754
View details for Web of Science ID A1996BF80L00098
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The failure mechanism of MOCVD TiN diffusion barrier at high temperature
Symposium on Materials Reliability in Microelectronics VI, at the 1996 MRS Spring Meeting
MATERIALS RESEARCH SOCIETY. 1996: 279–284
View details for Web of Science ID A1996BG81V00039
- In Situ Atomic Resolution Electron Microscopy of Metal-Mediated Crystallization of Semiconductors Materials Science Forum 1996; 204-206: 749-754
- In Situ Observation of the C49-to-C54 Phase Transformation in TiSi2 Thin Films by Transmission Electron Microscopy Jpn. J. Appl. Phys. Lett. 1996; 35: L479-481
- Effects of Pt Addition on the Magnetic and Crystallographic Properties of Co-Cr-Pt Thin Film Media J. Magn. Magn. Mater. 1996; 152: 265-273
- Structural Comparisons of Ion-Beam and RF Sputter-Deposited GMR Spin Valves by High Resolution Transmission Electron Microscopy J. Appl. Phys. 1996; 79: 6393-6395
- Strategies and Opportunities for In-Situ Electron Microscopy edited by Munoz, E., M. Rivera 1996
- Micromagnetic and Experimental Studies of CoPtCr Polycrystalline Thin Film Media with Bicrystal Microstructure IEEE Trans. Magn. 1996; 31: 2821-2823
- Microstructure-Magnetic Property Relationships in CoCrPt Magnetic Thin Films IEEE Trans. Magn. 1996; 32: 3587-3589
- A Failure Mechanism of MOCVD TiN Diffusion Barriers at High Temperatures 1996
- Growth of a' Nitrogen-Martensite and Fe16N2 Films Using (001) Silicon Substrates IEEE Trans. Magn. 1996; 32: 3503-3505
- In Situ Electron and Tunneling Microscopy of Dynamic Processes edited by Sharma, R., Gai, P., L., Gajdardziska-Josifovska, M. 1996
- Thin Film Media With and Without Bicrystal Cluster Structure on Glass Ceramic Structures IEEE Trans. Magn. 1996; 32: 3599-3601
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Physical characterization of two-dimensional doping profiles for process modeling
3rd International Workshop on the Measurement and Characterization of Ultra-Shallow Doping Profiles in Semiconductors
A V S AMER INST PHYSICS. 1996: 231–35
View details for Web of Science ID A1996TV71000040
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MICROSTRUCTURAL EVOLUTION OF NIFE/AG MULTILAYERS STUDIED BY X-RAY-DIFFRACTION AND IN-SITU HIGH-RESOLUTION TEM
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
1995; 151 (1-2): 24-32
View details for Web of Science ID A1995TJ23000007
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KERR ROTATIONS AND ANISOTROPY IN (PT/CO/PT)/X MULTILAYERS
33rd Annual Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1995: 3337–42
View details for Web of Science ID A1995TD55600233
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MICROMAGNETIC AND EXPERIMENTAL STUDIES OF COPTCR POLYCRYSTALLINE THIN-FILM MEDIA WITH BICRYSTAL MICROSTRUCTURE
33rd Annual Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1995: 2821–23
View details for Web of Science ID A1995TD55600078
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HIGH-DENSITY RECORDING CHARACTERISTICS OF SPUTTERED BARIUM FERRITE THIN-FILMS
33rd Annual Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1995: 2749–51
View details for Web of Science ID A1995TD55600054
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INTERFACIAL REACTIONS IN THE ZR-SI SYSTEM STUDIED BY IN-SITU TRANSMISSION ELECTRON-MICROSCOPY
JOURNAL OF APPLIED PHYSICS
1995; 78 (8): 4982-4987
View details for Web of Science ID A1995RY39600025
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REACTION-MEDIATED TEXTURING OF BARIUM FERRITE MAGNETIC THIN-FILMS ON ZNO UNDERLAYER
JOURNAL OF MATERIALS RESEARCH
1995; 10 (9): 2343-2349
View details for Web of Science ID A1995RQ71400024
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STRUCTURE AND CORROSION PROPERTIES OF AL/SI AND FE/ZR MULTILAYERS
3rd US/Japan Seminar on Development and Environmental Characteristics of New Materials
ELSEVIER SCIENCE SA. 1995: 19–24
View details for Web of Science ID A1995RQ43900004
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INTERFACE STRUCTURE AND PERPENDICULAR MAGNETIC-ANISOTROPY IN PT/CO MULTILAYERS
JOURNAL OF APPLIED PHYSICS
1995; 77 (8): 3953-3959
View details for Web of Science ID A1995QU38700053
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DIRECT FORMATION OF ORDERED COPT AND FEPT COMPOUND THIN-FILMS BY SPUTTERING
APPLIED PHYSICS LETTERS
1995; 66 (13): 1692-1694
View details for Web of Science ID A1995QN76700040
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METAL-MEDIATED CRYSTALLIZATION OF AMORPHOUS-SILICON IN SILICON SILVER LAYERED SYSTEMS
PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES
1995; 71 (2): 163-178
View details for Web of Science ID A1995QH55400005
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CRYSTALLIZATION OF AMORPHOUS-CARBON IN CARBON-COBALT LAYERED THIN-FILMS
ACTA METALLURGICA ET MATERIALIA
1995; 43 (2): 471-484
View details for Web of Science ID A1995QG02800007
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METAL-MEDIATED CRYSTALLIZATION OF AMORPHOUS-GERMANIUM IN GERMANIUM SILVER LAYERED SYSTEMS
PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES
1995; 71 (2): 179-199
View details for Web of Science ID A1995QH55400006
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Quantitative measurement of interface fracture energy in multi-layer thin film structures
5th Symposium on Materials Reliability in Microelectronics, at the 1995 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1995: 91–96
View details for Web of Science ID A1995BE31N00011
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TEM study of crystallization of a-SiC in contact with silver
Symposium on Structure and Properties of Multilayered Thin Films, at the 1995 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1995: 39–44
View details for Web of Science ID A1995BE43P00006
- HREM of Ultra-thin Oxides 1995
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Growth and characterization of FePt compound thin films
Symposium on Magnetic Ultrathin Films, Multilayers and Surfaces
MATERIALS RESEARCH SOC. 1995: 91–96
View details for Web of Science ID A1995BE33K00013
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Study of diffusion barrier performance in MOCVD TiN by transmission electron microscopy
5th Symposium on Materials Reliability in Microelectronics, at the 1995 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1995: 205–209
View details for Web of Science ID A1995BE31N00025
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In situ TEM study of reactions in iron amorphous carbon layered thin films
Symposium on Structure and Properties of Multilayered Thin Films, at the 1995 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1995: 45–50
View details for Web of Science ID A1995BE43P00007
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Interface reaction enhanced epitaxial growth of barium ferrite magnetic thin films
Symposium on Structure and Properties of Interfaces in Ceramics, at the 1994 Fall Meeting of the Materials-Research-Society
MATERIALS RESEARCH SOC. 1995: 165–170
View details for Web of Science ID A1995BD52Z00025
- In Situ TEM Study of Reactions in Iron/Amorphous Carbon Layered Thin Films 1995
- (Pt/Co/Pt)/X Multilayer Thin Films for Magneto-Optic Media 1995
- High Density Recording Characteristics of Sputtered Barium Ferrite Thin Films IEEE Trans. Magn. 1995; 31: 2749-2751
- Direct Formation of Ordered CoPt and FePt Compound Thin Films by Sputtering Appl. Phys. Lett. 1995; 66: 1692-1694
- Study of Diffusion Barrier Performance of MOCVD-TiN 1995
- TEM study of Crystallization of a-SiC in Contact with Silver 1995
- Interface Reaction Enhanced Epitaxial Growth of Barium Ferrite Magnetic Thin Films 1995
- Formation of Epitaxial (001) Ordered FePd Films from Multilayer Precursors 1995
- In Situ Electron Microscopy and its Application to Semiconductor Reactions at High Resolution 1995
- Thermochemical Properties and Phase Diagrams in Properties of Metal Silicides edited by Maex, K., van Rossum, M. Inst. Elec. Eng’rs, London. 1995: 95–152
- Formation of Epitaxial (001) Ordered FePd Films from Multilayer Precursors J. Mag. Soc. Jpn. 1995; 19: 399-403
- Crystallization of Amorphous Carbon in Carbon-Cobalt Layered Thin Films Acta Metall. Mater. 1995; 43: 471-484
- Metal-Mediated Crystallization of Amorphous Germanium in Germanium-Silver Layered Systems Philos. Mag. B 1995; 71: 179-199
- Microstructural Evolution of NiFe/Ag Multilayers Studied by X-ray Diffraction and In Situ TEM J. Magn. Magn. Mater. 1995; 151: 24-32
- Pt/Co/Pt)/X Multilayer Thin Films for Magneto-Optic Media J. Mag. Soc. Jpn. 1995; 19: 201-204
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Crystallization in metal-metalloid multilayers
Symposium on Structure and Properties of Multilayered Thin Films, at the 1995 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1995: 3–8
View details for Web of Science ID A1995BE43P00001
- Interfacial Reactions in the Zr/Si System Studied by In-Situ TEM J. Appl. Phys. 1995; 78: 4982-4987
- Interface Structure and Perpendicular Magnetic Anisotropy in Pt/Co Multilayers J. Appl. Phys. 1995; 77: 3953-3959
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Observation of micromagnetic structure in computer hard disks by Lorentz transmission electron microscopy
Symposium on Magnetic Ultrathin Films, Multilayers and Surfaces
MATERIALS RESEARCH SOC. 1995: 21–26
View details for Web of Science ID A1995BE33K00004
- Microstructural, Magnetic and Magneto-Optical Properties of (100) and (111) Oriented Thick ‘FCC’ Cobalt Single Crystal 1995
- Microstructural, Magnetic and Magneto-Optical Properties of (100) and (111) Oriented Thick ‘FCC’ Cobalt Single Crystal J. Mag. Soc. Jpn. 1995; 19 (S1): 267-270
- Reaction Mediated Texturing of Barium Ferrite Magnetic Thin Films J. Mater. Res. 1995; 10: 2343-2349
- Metal-Mediated Crystallization of Amorphous Silicon in Silicon-Silver Layered Systems Philos. Mag. B 1995; 71: 163-178
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HREM analysis of ultra-thin oxides
4th International Conference on Solid-State and Integrated-Circuit Technology
PUBLISHING HOUSE ELECTRONICS INDUSTRY. 1995: A739–A741
View details for Web of Science ID A1995BF21N00221
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OXYGEN COULOMETRIC TITRATION STUDY OF M-BA-FERRITE
SOLID STATE IONICS
1994; 73 (3-4): 185-188
View details for Web of Science ID A1994PR98500004
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TEMPERATURE AND ORIENTATION EFFECTS ON THE MAGNETIC-PROPERTIES OF DOPED BARIUM FERRITE THIN-FILMS
6th Joint Magnetism and Magnetic Materials-Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1994: 4050–52
View details for Web of Science ID A1994PU42900083
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LONGITUDINAL RECORDING PERFORMANCE OF SPUTTERED BARIUM FERRITE MEDIA ON A CARBON RIGID DISK SUBSTRATE
6th Joint Magnetism and Magnetic Materials-Intermag Conference
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1994: 4047–49
View details for Web of Science ID A1994PU42900082
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IN-SITU HREM - APPLICATION TO METAL-MEDIATED CRYSTALLIZATION
International Symposium on High-Voltage and High-Resolution Electron Microscopy - Achievements and Future Developments
ELSEVIER SCIENCE BV. 1994: 225–32
View details for Web of Science ID A1994PV84400023
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FORMATION OF EPITAXIAL FERROMAGNETIC INTERMETALLICS BY SOLID-STATE REACTION OF EPITAXIAL MULTILAYERS
AMER CHEMICAL SOC. 1994: 518-INOR
View details for Web of Science ID A1994PA26102693
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CONTAMINATION CONTROL RESEARCH ROUND-TABLE MEETS
JOURNAL OF THE IES
1994; 37 (4): 10-11
View details for Web of Science ID A1994PD27500002
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(PT/CO/PT)/X MULTILAYER FILMS WITH HIGH KERR ROTATIONS AND LARGE PERPENDICULAR MAGNETIC ANISOTROPIES
APPLIED PHYSICS LETTERS
1994; 64 (24): 3337-3339
View details for Web of Science ID A1994NQ97900046
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IN-SITU DYNAMIC HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY - APPLICATION TO PT/GAAS INTERFACIAL REACTIONS
ULTRAMICROSCOPY
1994; 54 (2-4): 166-178
View details for Web of Science ID A1994PA59800008
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STUDIES OF MATERIAL REACTIONS BY IN-SITU HIGH-RESOLUTION ELECTRON-MICROSCOPY
MRS BULLETIN
1994; 19 (6): 26-31
View details for Web of Science ID A1994NT03600004
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THERMOCHEMICAL STABILITY OF BAFE12O19 AND BAFE2O4 AND PHASE-RELATIONS IN THE BA-FE-O TERNARY-SYSTEM
JOURNAL OF MATERIALS RESEARCH
1994; 9 (6): 1499-1512
View details for Web of Science ID A1994NN76400021
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NOISE PROPERTIES AND MICROSTRUCTURE OF ORIENTED COCRTA/CR MEDIA
38th Annual Conference on Magnetism and Magnetic Materials (MMM 93)
AMER INST PHYSICS. 1994: 6144–46
View details for Web of Science ID A1994NN73400251
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METAL-CONTACT-INDUCED CRYSTALLIZATION OF SEMICONDUCTORS
8th International Conference on Rapidly Quenched and Metastable Materials
ELSEVIER SCIENCE SA. 1994: 426–432
View details for Web of Science ID A1994NN06000089
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STRUCTURE-PROPERTY CORRELATIONS IN PT/CO MULTILAYERS FOR MAGNETOOPTIC RECORDING
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
1994; 134 (1): 173-184
View details for Web of Science ID A1994NP95700025
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CRYSTALLIZATION OF CO-SPUTTERED AMORPHOUS COBALT-CARBON ALLOYS - MORPHOLOGY AND KINETICS OF SPHERULITIC GROWTH
8th International Conference on Rapidly Quenched and Metastable Materials
ELSEVIER SCIENCE SA. 1994: 297–302
View details for Web of Science ID A1994NN06000063
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CRYSTALLIZATION OF CO-SPUTTERED AMORPHOUS COBALT CARBON ALLOYS
ACTA METALLURGICA ET MATERIALIA
1994; 42 (4): 1231-1247
View details for Web of Science ID A1994NA12500018
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ATOMIC-ORDER PLANARIZATION OF ULTRATHIN SIO2/SI(001) INTERFACES
1993 International Conference on Solid State Devices and Materials (SSDM 93)
JAPAN SOC APPLIED PHYSICS. 1994: 388–94
View details for Web of Science ID A1994MV67800007
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ON THE PERPENDICULAR MAGNETIC-ANISOTROPY OF PT CO MULTILAYERS - STRUCTURE-PROPERTY RELATIONSHIPS
Symposium on Polycrystalline Thin Films: Structure, Texture, Properties and Applications, at the 1994 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1994: 369–374
View details for Web of Science ID A1994BB59L00051
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Observations of ferroelectric domain walls in KTP by HREM
13th International Congress on Electron Microscopy
EDITIONS PHYSIQUE. 1994: 233–234
View details for Web of Science ID A1994BE09Y00113
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EFFECT OF INTERLAYERS UPON TEXTURE AND MAGNETIC-PROPERTIES IN CO ALLOY MULTILAYER FILMS FOR LONGITUDINAL MAGNETIC RECORDING
Symposium on Polycrystalline Thin Films: Structure, Texture, Properties and Applications, at the 1994 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1994: 381–386
View details for Web of Science ID A1994BB59L00053
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TEM AND IN-SITU HREM FOR STUDYING METAL-SEMICONDUCTOR INTERFACIAL REACTIONS
International Meeting on Reactive Phase Formation at Interfaces and Diffusion Processes
TRANSTEC PUBLICATIONS LTD. 1994: 111–120
View details for Web of Science ID A1994BB67Z00009
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IN-SITU TEM OBSERVATION OF INTERFACIAL REACTIONS IN THE ZR/SI SYSTEM
Symposium on Advanced Metallization for Devices and Circuits: Science, Technology and Manufacturability
MATERIALS RESEARCH SOC. 1994: 481–485
View details for Web of Science ID A1994BB59J00061
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In situ HREM of phase reactions (invited)
13th International Congress on Electron Microscopy
EDITIONS PHYSIQUE. 1994: 429–430
View details for Web of Science ID A1994BE09Y00207
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CORRELATION OF MICRO-STRUCTURAL, MICRO-CHEMICAL AND MICRO-MAGNETIC PROPERTIES OF LONGITUDINAL RECORDING MEDIA USING CM20FEG LORENTZ TEM
52nd Annual Meeting of the Microscopy-Society-of-America/29th Annual Meeting of the Microbeam-Analysis-Society
SAN FRANCISCO PRESS INC. 1994: 892–893
View details for Web of Science ID A1994BC03U00446
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TRANSMISSION ELECTRON-MICROSCOPY OF MOCVD TITANIUM NITRIDE FILMS
Symposium on Advanced Metallization for Devices and Circuits: Science, Technology and Manufacturability
MATERIALS RESEARCH SOC. 1994: 735–740
View details for Web of Science ID A1994BB59J00096
- Transmission Electron Microscopy of MOCVD Titanium Nitride Films 1994
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ATOMICALLY LAYERED STRUCTURES FOR PERPENDICULAR MAGNETIC INFORMATION-STORAGE
Symposium on Polycrystalline Thin Films: Structure, Texture, Properties and Applications, at the 1994 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1994: 359–367
View details for Web of Science ID A1994BB59L00050
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NICKEL MEDIATED TRANSFORMATION OF AMORPHOUS CARBON TO GRAPHITE
Symposium on Novel Forms of Carbon II, at the 1994 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1994: 31–36
View details for Web of Science ID A1994BC30W00005
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CHARACTERIZATION OF SPUTTERED BARIUM FERRITE THIN-FILMS ON SILICON-NITRIDE COATED CARBON SUBSTRATES
Symposium on Epitaxial Oxide Thin Films and Heterostructures, at the MRS Spring Meeting
MATERIALS RESEARCH SOC. 1994: 59–64
View details for Web of Science ID A1994BB69Z00008
- Polycrystalline Thin Films-Structure, Texture, Properties and Applications edited by Barmak, K., Parker, M., A., Floro, J., F. 1994
- Roughness Control and Electrical Properties of SiO/Si (001) Interfaces First International Symposium on Control of Semiconductor Interfaces, Elsevier, New York 1994: 405-410
- Reactions at Semiconductor Metal Interfaces First International Symposium on Control of Semiconductor Interfaces, Elsevier, New York 1994: 247-254
- Studies of Material Reactions by In-Situ High Resolution Electron Microscopy (HREM) MRS Bull. 1994; 6 (19): 26-31
- Effect of Interlayers Upon Texture and Magnetic Properties in Co Alloy Multilayers for Longitudinal Magnetic Recording 1994
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CORRELATION OF STRUCTURE AND PROPERTIES IN THIN-FILM MAGNETIC MEDIA
Symposium on Polycrystalline Thin Films: Structure, Texture, Properties and Applications, at the 1994 MRS Spring Meeting
MATERIALS RESEARCH SOC. 1994: 297–302
View details for Web of Science ID A1994BB59L00041
- Atomic-Order Planarization of Ultra-Thin SiO2/Si (001) Interfaces Jpn. J. Appl. Phys. 1994; 33: 388-394
- Longitudinal Recording Performance of Doped Barium Ferrite Magnetic Thin Films IEEE Trans. Magn. 1994; 30: 4047-4049
- Temperature and Orientation Effects on Magnetic Properties of Barium Ferrite Thin Films IEEE Trans. Magn. 1994; 30: 4050-4052
- In Situ HREM: Application to Metal-Mediated Crystallization Ultramicroscopy 1994; 56: 225-232
- Dynamic High Resolution Transmission Electron Microscopy: Application to Pt/GaAs Interfacial Reactions Ultramicroscopy 1994; 54: 166-178
- Crystallization of Co-sputtered Amorphous Cobalt-Carbon Alloys: Morphology and Kinetics of Spherulitic Growth Mater. Sci. Eng. 1994; A179/A180: 297-302
- Nickel Mediated Transformation of Amorphous Carbon to Graphite 1994
- In-Situ TEM Observation of Interfacial Reactions in the Zr/Si System 1994
- Microscopic Interfacial Phenomena During Solid Phase Crystallization of Amorphous Silicon Thin Films: In-Situ CTEM and HREM Studies 1994
- TEM and In Situ HREM for Studying Metal-Semiconductor Interfacial Reactions edited by Limoge, Y., Bocquet, J., L. 1994
- Structure-Property Correlations in Pt/Co Multilayers for Magneto-Optic Recording J. Magn. Magn. Mater. 1994; 134: 173-184
- Metal-Contact Induced Crystallization of Semiconductors Mater. Sci. Eng. A 1994; A179/A180: 426-432
- Correlation of Micro-structural, Micro-chemical and Micro-magnetic Properties of Longitudinal Recording Media Using CM20 FEG Lorentz TEM 1994
- Effects of Substrate Temperature on Magnetic and Crystallographic Properties of Co-Cr-Pt/Cr Films Deposited by Laser Ablation Method 1994
- Atomically Layered Structures for Magnetic Information Storage 1994
- Characterization of Sputtered Magnetic Barium-Ferrite Thin Films on Silicon Nitride Coated High Density Amorphous Carbon Substrates 1994
- Reactions at Semiconductor Metal Interfaces 1994
- In Situ HREM of Phase Reactions 1994
- Oxygen Coulometric Titration Study of M Ba-Ferrite Solid State Ionics 1994; 73: 185-188
- On The Perpendicular Magnetic Anisotropy of Co/Pt Multilayers: Structure-Property Relationships 1994
- Crystallization of Co-sputtered Amorphous Cobalt-Carbon Alloys Acta Metall. Mater. 1994; 42: 1231-1247
- Observation of Ferroelectric Domain Walls in KTP by HREM 1994
- ³Roughness Control and Electrical Properties of SiO/Si (001) Interfaces 1994
- Thermochemical Stability of BaFe12O19 and BaFe2O4 and Phase Relations in the Ba-Fe-O Ternary System J. Mater. Res. 1994; 9: 1499-1512
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EPITAXIAL PTFE AND PTCO(001) THIN-FILMS WITH PERPENDICULAR MAGNETIC-ANISOTROPY
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 577–79
View details for Web of Science ID A1993MD35400165
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INFLUENCE OF INTERFACIAL DOPING WITH RARE-EARTH ELEMENTS ON THE MAGNETIC-PROPERTIES OF SELECTED CO/PT MULTILAYERS
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 275–78
View details for Web of Science ID A1993MD35400074
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CRYSTALLIZATION AND DECOMPOSITION OF CO-SPUTTERED AMORPHOUS SILICON-ALUMINUM THIN-FILMS
MATERIALS CHEMISTRY AND PHYSICS
1993; 35 (2): 99-113
View details for Web of Science ID A1993LT15400001
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STRUCTURE AND CORROSION PROPERTIES OF AL/SI MULTILAYERS
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 167–69
View details for Web of Science ID A1993MD35400046
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ANNEALING OF METAL METALLOID MULTILAYERS STUDIED BY IN-SITU ELECTRON-MICROSCOPY
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 108–12
View details for Web of Science ID A1993MD35400031
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ANNEALING EFFECT ON STRUCTURE OF FE/ZR MULTILAYERS
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 128–30
View details for Web of Science ID A1993MD35400036
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MICROSTRUCTURAL ANALYSIS OF MAGNETIC FE/PT MULTILAYER THIN-FILMS BY TRANSMISSION ELECTRON-MICROSCOPY
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 136–40
View details for Web of Science ID A1993MD35400038
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STRUCTURE AND CORROSION PROPERTIES OF FE/ZR MULTILAYERS
1ST INTERNATIONAL SYMP ON METALLIC MULTILAYERS ( MML 93 )
ELSEVIER SCIENCE BV. 1993: 105–7
View details for Web of Science ID A1993MD35400030
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ATOMIC-SCALE PLANARIZATION OF SIO2/SI(001) INTERFACES
APPLIED PHYSICS LETTERS
1993; 63 (5): 675-677
View details for Web of Science ID A1993LQ13300037
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EPITAXIAL TETRAGONAL PTCO (001) THIN-FILMS WITH PERPENDICULAR MAGNETIC-ANISOTROPY
JOURNAL OF APPLIED PHYSICS
1993; 74 (3): 1922-1928
View details for Web of Science ID A1993LQ12700071
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DIRECT OBSERVATION OF CRYSTALLIZATION IN SILICON BY IN-SITU HIGH-RESOLUTION ELECTRON-MICROSCOPY
4TH CONF ON FRONTIERS OF ELECTRON MICROSCOPY IN MATERIALS SCIENCE
ELSEVIER SCIENCE BV. 1993: 41–45
View details for Web of Science ID A1993LN79100006
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CRYSTALLOGRAPHIC ORIENTATION OF TEXTURED COCRTA/CR SPUTTERED THIN-FILM MEDIA FOR LONGITUDINAL RECORDING
JOURNAL OF APPLIED PHYSICS
1993; 73 (10): 5117-5124
View details for Web of Science ID A1993LD85100056
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EFFECT OF MICROSTRUCTURAL FEATURES ON MEDIA NOISE IN LONGITUDINAL RECORDING MEDIA
37TH ANNUAL CONF ON MAGNETISM AND MAGNETIC MATERIALS
AMER INST PHYSICS. 1993: 5566–68
View details for Web of Science ID A1993LD85400102
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TEM ANALYSIS OF CO-GD AND CO-GD MULTILAYER STRUCTURES
JOURNAL OF MATERIALS RESEARCH
1993; 8 (4): 771-774
View details for Web of Science ID A1993KV48700015
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EPITAXIAL PTFE(001) THIN-FILMS ON MGO(001) WITH PERPENDICULAR MAGNETIC-ANISOTROPY
APPLIED PHYSICS LETTERS
1993; 62 (6): 639-641
View details for Web of Science ID A1993KK92400034
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TRANSMISSION ELECTRON-MICROSCOPIC ANALYSIS OF MICROSTRUCTURAL FEATURES IN MAGNETIC RECORDING MEDIA
3RD MAGNETIC RECORDING CONF ( TMRC 92 )
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1993: 292–99
View details for Web of Science ID A1993KN28600043
- Atomic-Order Planarization of Ultra-Thin SiO2/Si (001) Interfaces 1993
- Application of High Resolution Electron Microscopy to the Study of Magnetic Thin Films and Multilayers 1993
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IN-SITU HIGH-RESOLUTION ELECTRON-MICROSCOPY OF METAL-CONTACT INDUCED CRYSTALLIZATION OF AMORPHOUS-SEMICONDUCTORS
8th Royal-Microscopical-Society Conference: Microscopy of Semiconducting Materials 1993 (MSM VIII)
IOP PUBLISHING LTD. 1993: 173–76
View details for Web of Science ID A1993BA56Y00036
- Microstructural Analysis of Magnetic Fe/Pt Multilayer Thin Films by Transmission Electron Microscopy J. Magn. Magn. Mater. 1993; 126: 136-140
- Deposition of Barium Ferrite Thin Films by RF Off-Axis Magnetron Sputtering 1993
- Crystallization and Decomposition of Co-sputtered Amorphous Silicon-Aluminum Thin Films Mater. Chem. Phys. 1993; 35: 99-113
- Transmission Electron Microscopic Analysis of Microstructural Features in Magnetic Recording Media IEEE Trans. Magn. 1993; 29: 292-299
- Reactions at the Ti-Si Interface Studied Using Hot Stage TEM 1993
- Transmission Electron Microscopy of Epitaxial Fe/Pt Multilayers 1993
- Real Time Lattice Imaging of Crystallization in Amorphous Silicon 1993
- Crystallographic Orientation of Textured CoCrTa/Cr Recording Media J. Appl. Phys. 1993; 73: 5117-5124
- Magnetic Properties and Crystallography of Selected Co/Pt Multilayers with Rare-Earth Doped Interface 1993
- Structural Properties of Uniaxial Tetragonal PtCo(001) and PtFe(001) Thin Films on MgO(001) 1993
- Evolution of Gd Thin Film Structure Due to Amorphization by Co-Deposition 1993
- Transmission Electron Microscopy Study of PtCo(001) and PtFe(001) Films Formed from Epitaxial Pt/Co and Pt/Fe Multilayers 1993
- Grain Separation Enhanced Magnetic Coercivity in Pt/Co Multilayers 1993
- A Solid State Electrochemical Technique to Study Barium Ferrite Thermodynamic Stability 1993
- Crystallization of Amorphous Germanium in Silver-Germanium Layered Systems 1993
- In-Situ High Resolution Electron Microscopy of Metal-Contact Induced Crystallization of Semiconductors 1993
- Reactions in Metal-Metalloid Multilayers 1993
- Magnetic and Magneto-Optic Properties of PtFe(001) and PtCo(001) Thin Films 1993
- Epitaxial Tetragonal PtCo(001) Thin Films with Perpendicular Magnetic Anisotropy J. Appl. Phys. 1993; 74: 1922-1928
- Epitaxial PtFe and PtCo(001) Thin Films with Perpendicular Magnetic Anisotropy J. Magn. Mag. Mater. 1993; 126: 577-579
- Annealing of Metal Multilayers Studied by In Situ High Resolution Electron Microscopy J. Magn. Magn. Mater. 1993; 126: 108-112
- Influence of Interfacial Doping with Rare Earth Elements on the Magnetic Properties of Selected Co/Pt Multilayers J. Magn. Mag. Mater. 1993; 126: 275-278
- TEM Analysis of Co-Gd and Cr-Gd Multilayer Structures J. Mater. Res. 1993; 8: 771-774
- Epitaxial PtFe (001) Thin Films on MgO (001) with Perpendicular Magnetic Anisotropy Appl. Phys. Lett. 1993; 62: 639-641
- Direct Solid State Phase Transformation from Co to Epitaxial CoSi in Co/Thin Ti/(100) Si Structure and its Application for Shallow Junction Formation 1993
- Production of c-Axis Oriented PtFe Thin Film with Perpendicular Magnetic Anisotropy 1993
- Production of c-Axis Oriented PtFe Thin Film with Perpendicular Magnetic Anisotropy J. Magn. Soc. Jap. 1993; 17 (S1): 40-43
- Transmission Electron Microscopy of Epitaxial Fe/Pt Multilayers J. Magn. Soc. Jap. 1993; 17 (S1): 113-116
- Direct Observation of Crystallization in Silicon by In Situ High Resolution Electron Microscopy Ultramicroscopy 1993; 51: 41-45
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STRUCTURAL-PROPERTIES OF ANISOTROPIC PTCO(001) AND PTFE(001) THIN-FILMS ON MGO(001)
SYMP ON PHASE TRANSFORMATIONS IN THIN FILMS - THERMODYNAMICS AND KINETICS, AT THE 1993 SPRING MEETING OF THE MATERIALS RESEARCH SOC
MATERIALS RESEARCH SOC. 1993: 9–14
View details for Web of Science ID A1993BY84Q00002
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EVOLUTION OF GD THIN-FILM STRUCTURE DUE TO AMORPHIZATION BY CO DEPOSITION
SYMP ON PHASE TRANSFORMATIONS IN THIN FILMS - THERMODYNAMICS AND KINETICS, AT THE 1993 SPRING MEETING OF THE MATERIALS RESEARCH SOC
MATERIALS RESEARCH SOC. 1993: 73–76
View details for Web of Science ID A1993BY84Q00013
- Structure and Magnetic Properties of Fe/Zr Multilayer Films 1993
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MAGNETIC AND MAGNETOOPTIC PROPERTIES OF PTFE(001) AND PTCO(001) THIN-FILMS
SYMP ON MAGNETIC ULTRATHIN FILMS : MULTILAYERS AND SURFACES, INTERFACES CHARACTIZATION, AT THE 1993 SPRING MEETING OF THE MATERIALS-RESEARCH-SOC
MATERIALS RESEARCH SOC. 1993: 805–810
View details for Web of Science ID A1993BZ22Y00110
- In Situ HREM of Interface Reactions 1993
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APPLICATION OF HIGH-RESOLUTION ELECTRON-MICROSCOPY TO THE STUDY OF MAGNETIC THIN-FILMS AND MULTILAYERS
SYMP ON MAGNETIC ULTRATHIN FILMS : MULTILAYERS AND SURFACES, INTERFACES CHARACTIZATION, AT THE 1993 SPRING MEETING OF THE MATERIALS-RESEARCH-SOC
MATERIALS RESEARCH SOC. 1993: 705–712
View details for Web of Science ID A1993BZ22Y00095
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TRANSMISSION ELECTRON-MICROSCOPY STUDY OF COPT(001) AND FEPT(001) FILMS FORMED FROM EPITAXIAL CO/PT AND FE/PT MULTILAYERS
SYMP ON PHASE TRANSFORMATIONS IN THIN FILMS - THERMODYNAMICS AND KINETICS, AT THE 1993 SPRING MEETING OF THE MATERIALS RESEARCH SOC
MATERIALS RESEARCH SOC. 1993: 15–20
View details for Web of Science ID A1993BY84Q00003
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CRYSTALLIZATION OF SILICON IN ALUMINUM AMORPHOUS-SILICON MULTILAYERS
PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES
1992; 66 (6): 749-765
View details for Web of Science ID A1992KC54900003
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MICROSTRUCTURE AND CRYSTALLOGRAPHY OF TEXTURED COCRTA/CR RECORDING MEDIA
ULTRAMICROSCOPY
1992; 47 (4): 437-446
View details for Web of Science ID A1992KG29200018
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EPITAXIAL PT(001), PT(110), AND PT(111) FILMS ON MGO(001), MGO(110), MGO(111), AND AL2O3(0001)
APPLIED PHYSICS LETTERS
1992; 61 (12): 1390-1392
View details for Web of Science ID A1992JN99100008
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AMORPHOUS PHASE FORMATION AND INITIAL INTERFACIAL REACTIONS IN THE PLATINUM GAAS SYSTEM
JOURNAL OF APPLIED PHYSICS
1992; 72 (5): 2036-2042
View details for Web of Science ID A1992JK80400053
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STRUCTURAL DETERMINATION OF AMORPHOUS NI-TI THIN-FILMS USING ELECTRON-DIFFRACTION ANALYSIS
ACTA METALLURGICA ET MATERIALIA
1992; 40 (8): 1855-1863
View details for Web of Science ID A1992JD12900008
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SIO2/SI INTERFACES STUDIED BY SCANNING TUNNELING MICROSCOPY AND HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
1992; 139 (3): 901-906
View details for Web of Science ID A1992HH07700047
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MODELING OF AGGLOMERATION IN POLYCRYSTALLINE THIN-FILMS - APPLICATION TO TISI2 ON A SILICON SUBSTRATE
JOURNAL OF APPLIED PHYSICS
1992; 71 (2): 720-724
View details for Web of Science ID A1992HA64500027
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REACTIONS AT THE TITANIUM-SILICON INTERFACE STUDIED USING HOT-STAGE TEM
SYMP ON ADVANCED METALLIZATION AND PROCESSING FOR SEMICONDUCTOR DEVICES AND CIRCUITS - 2
MATERIALS RESEARCH SOC. 1992: 227–231
View details for Web of Science ID A1992BX05U00028
- Reaction and Stability at VLSI Contact Interfaces 1992
- Two-Step Martensitic Transformations in TiNi (10% Cu) Shape Memory Alloys 1992
- Reactions at Solid Interfaces 1992
- Study of Semiconductor Metallization Problems by High Resolution Electron Microscopy and Thermodynamic Analysis 1992
- Crystallization of Amorphous Si in Al/Si Multilayers 1992
- Microstructure and Crystallography of Textured CoCrTa/Cr Sputtered Thin Film Media for Longitudinal Recording Ultramicroscopy 1992; 47: 437-446
- Structural Determination of Amorphous Ni-Ti Thin Films, Using Electron Diffraction Analysis Acta Metall. 1992; 40: 1855-1863
- Modeling of Agglomeration in Polycrystalline Thin Films: Application to TiSi2 on a Silicon Substrate J. Appl. Phys. 1992; 71: 720-724
- SiO2/Si Interfaces Studied by Scanning Tunneling Microscopy and High Resolution Transmission Electron Microscopy J. Electrochem. Soc. 1992; 139: 901-906
- Amorphous Phase Formation and the Initial Reactions at Pt/GaAs Interfaces 1992
- A Highly Reliable Sub-Half Micron Via and Interconnect Technology Using Al Alloy High-Temperature Sputter Filling 1992
- Reaction and Stability at VLSI Contact Interfaces Jpn. Soc. Appl. Phys. 1992: 1268
- Crystallization of Silicon in Aluminum/Amorphous-Silicon Multilayers Philos. Mag. B 1992; 66: 749-765
- Epitaxial Pt (001), Pt (110) and Pt (111) Films on MgO (001), MgO (110), MgO (111) and Al2O3 (0001) Appl. Phys. Lett. 1992; 61: 1390-1392
- Reaction and Stability at ULSI Circuit Interfaces 1992
- Crystallization of Amorphous Silicon-Aluminum Thin Films: In-Situ Observation and Thermal Analysis 1992
- A Highly Reliable Sub-Half Micron Via and Interconnect Technology Using Al Alloy High-Temperature Sputter Filling VLSI Tech. Dig. 1992: 74-75
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2-STEP MARTENSITIC TRANSFORMATIONS IN TINI(10-PERCENT CU) SHAPE MEMORY ALLOYS
SYMP ON SHAPE-MEMORY MATERIALS AND PHENOMENA - FUNDAMENTAL ASPECTS AND APPLICATIONS
MATERIALS RESEARCH SOC. 1992: 55–60
View details for Web of Science ID A1992BW94E00008
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METASTABLE AND EQUILIBRIUM DEFECT STRUCTURE OF II-VI/GAAS INTERFACES
SYMP AT THE 1991 ANNUAL MEETING OF THE MINERALS, METALS AND MATERIALS SOC : STRAIN RELAXATION IN EPITAXIAL FILMS
MINERALS METALS MATERIALS SOC. 1991: 805–14
View details for Web of Science ID A1991GH65700015
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STRUCTURE OF AN AMORPHOUS TI-SI ALLOY FORMED BY THERMAL-REACTION
JOURNAL OF NON-CRYSTALLINE SOLIDS
1991; 134 (1-2): 133-140
View details for Web of Science ID A1991GF66500019
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INTERFACE MICROSTRUCTURE OF TITANIUM THIN-FILM SILICON SINGLE-CRYSTAL SUBSTRATE CORRELATED WITH ELECTRICAL BARRIER HEIGHTS
JOURNAL OF APPLIED PHYSICS
1991; 70 (2): 827-832
View details for Web of Science ID A1991FY34100042
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AMORPHOUS PHASE FORMATION IN AN AS-DEPOSITED PLATINUM-GAAS INTERFACE
APPLIED PHYSICS LETTERS
1991; 58 (17): 1851-1853
View details for Web of Science ID A1991FJ59700016
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LOW-TEMPERATURE REACTIONS AT METAL-SEMICONDUCTOR INTERFACES
CONF ON MICROSCOPY OF SEMICONDUCTING MATERIALS
IOP PUBLISHING LTD. 1991: 283–287
View details for Web of Science ID A1991BV30N00056
- Reaction and Stability at Material Interfaces 1991
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EQUILIBRIUM DEFECT STRUCTURE OF ANNEALED II-VI/GAAS INTERFACES
CONF ON MICROSCOPY OF SEMICONDUCTING MATERIALS
IOP PUBLISHING LTD. 1991: 523–526
View details for Web of Science ID A1991BV30N00102
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LOW-TEMPERATURE REACTIONS AT METAL-SEMICONDUCTOR INTERFACES
INSTITUTE OF PHYSICS CONFERENCE SERIES
1991: 283-287
View details for Web of Science ID A1991HJ30700056
- Amorphous-Phase Formation and Initial Reactions at Pt/GaAs Interfaces 1991
- An In Situ HREM Study of Crystal Nucleation in Amorphous Silicon Thin Films 1991
- Evidence for a Grain Boundary Grooving Model of Agglomeration in Polycrystalline TiSi2 Thin Films 1991
- Crystallization of Amorphous Si in Si/Al Multilayers 1991
- Structure and Thermodynamics of Amorphous Titanium-Silicon Produced by Solid- State Interdiffusion 1991
- Metastable and Equilibrium Defect Structure of II/VI GaAs Interfaces J. Electron. Mater. 1991; 20: 805-814
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AN INSITU HREM STUDY OF CRYSTAL NUCLEATION IN AMORPHOUS-SILICON THIN-FILMS
SYMP ON THE EVOLUTION OF THIN-FILM AND SURFACE MICROSTRUCTURE
MATERIALS RESEARCH SOC. 1991: 627–632
View details for Web of Science ID A1991BT82M00097
- In Situ Heating Studies at High Resolution 1991
- Structure of an Amorphous Ti-Si Alloy Formed by Thermal Reaction J. Non-Cryst. Solids 1991; 134: 133-140
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THERMOMECHANICAL STRENGTHENING OF B2 INTERMETALLICS
SYMP ON MODELING THE DEFORMATION OF CRYSTALLINE SOLIDS, AT THE 1991 ANNUAL MEETING OF THE MINERALS, METALS AND MATERIALS SOC
MINERALS, METALS & MATERIALS SOC. 1991: 387–393
View details for Web of Science ID A1991BV82Q00026
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EQUILIBRIUM DEFECT STRUCTURE OF ANNEALED II-VI/GAAS INTERFACES
INSTITUTE OF PHYSICS CONFERENCE SERIES
1991: 523-526
View details for Web of Science ID A1991HJ30700102
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DEFORMATION, TWINNING AND THERMOMECHANICAL STRENGTHENING OF TI50NI47FE3
ACTA METALLURGICA ET MATERIALIA
1990; 38 (12): 2601-2612
View details for Web of Science ID A1990EN96200023
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SIO2/SI INTERFACES STUDIED BY STM AND HRTEM .2.
3RD ( 2ND INTERNATIONAL ) MICROPROCESS CONF ( MPC 90 )
JAPAN J APPLIED PHYSICS. 1990: 2665–70
View details for Web of Science ID A1990EN83000071
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PHASE REACTIONS AT SEMICONDUCTOR METALLIZATION INTERFACES
SYMP AT THE 1990 ANNUAL MEETING OF THE METALLURGICAL SOC : METALLIZATIONS FOR ELECTRONICS APPLICATIONS
MINERALS METALS MATERIALS SOC. 1990: 1171–75
View details for Web of Science ID A1990EN80100004
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A THERMODYNAMIC APPROACH FOR INTERPRETING METALLIZATION LAYER STABILITY AND THIN-FILM REACTIONS INVOLVING 4 ELEMENTS - APPLICATION TO INTEGRATED-CIRCUIT CONTACT METALLURGY
JOURNAL OF APPLIED PHYSICS
1990; 68 (3): 1043-1049
View details for Web of Science ID A1990DP61600024
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STUDY OF INTERFACIAL REACTIONS IN METAL-SILICON AND RELATED SYSTEMS BY HIGH-RESOLUTION ELECTRON-MICROSCOPY AND THERMODYNAMIC ANALYSIS
MATERIALS TRANSACTIONS JIM
1990; 31 (7): 628-635
View details for Web of Science ID A1990DU89000017
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THICKNESS MEASUREMENTS AND GROWTH-KINETICS OF THIN SIO2 LAYERS
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
1990; 137 (1): 279-283
View details for Web of Science ID A1990CH81500052
- HRTEM and Nano-scale Microanalysis of the Titanium/Silicon Interfacial Reaction Correlated with Electrical Properties 1990
- In Situ HREM Observations of Crystallization in LPCVD Amorphous Silicon 1990
- Structure of the Ti-Single Crystal Si Interface 1990
- Thermodynamic Stability of PtAl Thin Films on GaAs 1990
- A Phase Diagram Approach for Predicting Reactions in Al/TiW (-Nitride) Thin-Film Systems 1990
- Interface Microstructure of Titanium Thin-Film / Silicon-Crystal Single Substrate, Correlated with Electrical Barrier Heights J. Appl. Phys. 1990; 70: 827-832
- SiO2/Si Interfaces Studied by STM and HRTEM (II) Jpn. J. Appl. Phys. 1990; 29: 2665-2670
- Study of Interfacial Reactions in Metal-Silicon and Related Interfacial Reactions by High Resolution Electron Microscopy and Thermodynamic Analysis Mater. Trans. Jpn. Inst. Met. 1990; 31: 628-635
- A Thermodynamic Approach for Interpreting Metallization Layer Stability and Thin-Film Reactions Involving Four Elements: Application to Integrated Circuit Contact Metallurgy J. Appl. Phys. 1990; 68: 1043-1049
- Thickness Measurements and Growth Kinetics of Thin SiO2 Layers J. Electrochem. Soc. 1990; 137: 279-283
- Microstructure-Property Studies for Semiconductor Interfaces Using High- Resolution Electron Microscopy edited by Craighead, H., G. , Gibson, J., M. 1990
- Twinning in Ternary Ti50Ni(50-x)Mx Alloys 1990
- High Resolution Electron Microscopy of Defects in Materials edited by Sinclair, R., Smith, D., J., Dahmen, U. 1990
- Metastable Phase Formation in Thin Films and Multilayers MRS Bull. 1990; 2 (15): 19-28
- Characterization of Metal Silicide/Silicon Interfaces 1990
- SiO2/Si Interfaces Studied by STM and HRTEM 1990
- In Situ High-Resolution Electron Microscopy 1990
- Mechanical Twinning and Plasticity in Ti-Ni-Fe(3%) edited by Muddle, B., C. 1990
- Deformation, Twinning and Thermo-Mechanical Strengthening of Ti50Ni47Fe3 Acta Metall. 1990; 38: 2601-2612
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AMORPHOUS SILICIDE FORMATION BY THERMAL-REACTION - A COMPARISON OF SEVERAL METAL-SILICON SYSTEMS
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
1989; 7 (3): 1479-1483
View details for Web of Science ID A1989U715300171
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MORPHOLOGY OF THE SILICON IMPLANTED INTERFACE OF A POLYSILICON SINGLE-CRYSTAL SILICON STRUCTURE
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
1989; 39 (1-4): 334-337
View details for Web of Science ID A1989T863200070
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A HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY OF THE FINE-STRUCTURE IN A TRENCH CAPACITOR
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
1989; 136 (2): 511-518
View details for Web of Science ID A1989T291400042
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STRUCTURE AND ELECTRICAL-PROPERTIES OF INTERFACES BETWEEN SILICON FILMS AND N+ SILICON-CRYSTALS
JOURNAL OF APPLIED PHYSICS
1989; 65 (2): 668-671
View details for Web of Science ID A1989R720400040
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INTERFACIAL REACTIONS ON ANNEALING MOLYBDENUM-SILICON MULTILAYERS
JOURNAL OF APPLIED PHYSICS
1989; 65 (2): 474-480
View details for Web of Science ID A1989R720400009
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REACTION AND STRUCTURE AT METAL-SEMICONDUCTOR INTERFACES
CONF ON MICROSCOPY OF SEMICONDUCTING MATERIALS
IOP PUBLISHING LTD. 1989: 599–607
View details for Web of Science ID A1989BT32E00094
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REACTION AND STRUCTURE AT METAL-SEMICONDUCTOR INTERFACES
INSTITUTE OF PHYSICS CONFERENCE SERIES
1989: 599-607
View details for Web of Science ID A1989FN49500094
- Amorphous Silicide Formation by Thermal Reaction: A Comparison of Several Metal-Silicon Systems J. Vac. Sci. Technol. A 1989; 7: 1479-1483
- Twinless Martensite in TiNiCu Shape Memory Alloys 1989
- Structure and Reaction at Metal-Semiconductor Interfaces 1989
- Reactions at Metal-Semiconductor Interfaces 1989
- Morphology of the Silicon Implanted Interface of a Polysilicon/Single Crystal Silicon Structure Jpn. Nucl. Instr. Meth. Phys. Res. B 1989; 39: 334-337
- Quaternary Phase Equilibria in the Ti-Si-N-O System: Stability of Metallization Layers and Prediction of Thin Film Reactions 1989
- HREM In Situ Annealing of the CdTe/GaAs Heterojunction 1989
- Transmission Electron Microscopy and High Resolution Scanning Electron Microscopy of Co-Ni-Pt Thin Film Magnetic Recording Media 1989
- Phase Equilibria at Semiconductor Interfaces edited by Smith, F., W. 1989
- Structure and Electrical Properties of Interfaces Between Silicon Films and n+ Silicon Crystals J. Appl. Phys. 1989; 65: 668-671
- A High-Resolution Electron Microscopy Study of the Fine Structure in a Trench Capacitor J. Electrochem. Soc. 1989; 136: 511-518
- In Situ Annealing Transmission Electron Microscopy (TEM) Study of Ti/GaAs and Ni/GaAs Interfacial Reactions 1989
- Structure and Reaction at Metal-Semiconductor Interfaces Jpn. Soc. Appl. Phys., Catalog No. AP892228 1989: 29-33
- In Situ High Resolution Electron Microscopy 1989
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COMPRESSIVE DEFORMATION AND FRACTURE IN WC MATERIALS
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
1988; 106: 299-303
View details for Web of Science ID A1988R829600001
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PHASE-DIAGRAMS IN SEMICONDUCTOR METALLIZATION
MINERALS METALS MATERIALS SOC. 1988: 44–44
View details for Web of Science ID A1988R143400377
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THE DEVELOPMENT OF INSITU HIGH-RESOLUTION ELECTRON-MICROSCOPY
ACTA CRYSTALLOGRAPHICA SECTION A
1988; 44: 965-975
View details for Web of Science ID A1988R253400029
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HIGH-RESOLUTION AND INSITU TEM STUDIES OF ANNEALING OF TI-SI MULTILAYERS
JOURNAL OF THE LESS-COMMON METALS
1988; 140: 139-148
View details for Web of Science ID A1988N867700017
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INTERFACIAL REACTIONS IN THE TI GAAS SYSTEM
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
1988; 6 (3): 1473-1477
View details for Web of Science ID A1988N974800035
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STRUCTURAL DETERMINATION OF SMALL AMORPHOUS VOLUMES BY ELECTRON-DIFFRACTION
JOURNAL OF NON-CRYSTALLINE SOLIDS
1988; 101 (2-3): 213-222
View details for Web of Science ID A1988N802200008
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DISORDERED INTERMIXING AT THE PLATINUM-SILICON INTERFACE DEMONSTRATED BY HIGH-RESOLUTION CROSS-SECTIONAL TRANSMISSION ELECTRON-MICROSCOPY, AUGER-ELECTRON SPECTROSCOPY, AND MEV ION CHANNELING
JOURNAL OF APPLIED PHYSICS
1988; 63 (3): 689-692
View details for Web of Science ID A1988L836200013
- Interfacial Reactions in the Ti/GaAs System J. Vac. Sci. Technol. A 1988; 6: 1473-1477
- Microstructures of Polysilicon 1988
- High-resolution and In Situ TEM Studies of Annealing of Ti-Si Multilayers J. Less Common Metals 1988; 140: 139-148
- Disordered Intermixing at the Platinum-Silicon Interface Demonstrated by High-resolution Cross-sectional Transmission Electron Microscopy, Auger Electron Spectroscopy and MeV Ion Channeling J. Appl. Phys. 1988; 63: 689-692
- Structural Determination of Small Amorphous Volumes by Electron Diffraction J. Non-Cryst. Solids 1988; 101: 213-222
- In-Situ and High-Resolution TEM Observation of Interfacial Reactions in Metal- Silicon Multilayers 1988
- The Development of In Situ High Resolution Electron Microscopy 1988; 44: 965-975
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PHASE-DIAGRAMS AND INSITU HIGH-RESOLUTION ELECTRON-MICROSCOPY OF METAL-SEMICONDUCTOR SYSTEMS
MINERALS METALS MATERIALS SOC. 1987: A7–A8
View details for Web of Science ID A1987K763800063
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KINETICS AND OXIDE COMPOSITION FOR THERMAL-OXIDATION OF CADMIUM TELLURIDE
JOURNAL OF APPLIED PHYSICS
1987; 62 (4): 1469-1476
View details for Web of Science ID A1987J402800052
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HIGH-RESOLUTION ELECTRON-MICROSCOPY AND SCANNING TUNNELING MICROSCOPY OF NATIVE OXIDES ON SILICON
SCIENCE
1987; 237 (4815): 630-633
Abstract
High-resolution transmission electron microscopy and scanning tunneling microscopy have been combined to examine the structure of the thin "native" oxide that forms on silicon surfaces at room temperature. Differences in the cleaning procedures for silicon wafers may affect the morphology of this oxide and critically influence further processing on the silicon substrates. An etch that ended with a dip in hydrofluoric acid provided a thinner oxide and a lower interface step density than did a sulfuric peroxide treatment. The availability of complementary information from high-resolution transmission electron microscopy and scanning tunneling microscopy is discussed.
View details for Web of Science ID A1987J472200024
View details for PubMedID 17758564
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PHASE-EQUILIBRIA IN METAL-GALLIUM-ARSENIC SYSTEMS - THERMODYNAMIC CONSIDERATIONS FOR METALLIZATION MATERIALS
JOURNAL OF APPLIED PHYSICS
1987; 61 (6): 2195-2202
View details for Web of Science ID A1987G327200014
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THE EVOLUTION OF SI/SIO2 INTERFACE ROUGHNESS
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
1987; 134 (3): 741-746
View details for Web of Science ID A1987G410200046
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AMORPHOUS TI-SI ALLOY FORMED BY INTERDIFFUSION OF AMORPHOUS SI AND CRYSTALLINE TI MULTILAYERS
JOURNAL OF APPLIED PHYSICS
1987; 61 (4): 1359-1364
View details for Web of Science ID A1987F969900016
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HIGH-RESOLUTION ELECTRON-MICROSCOPY OF STRUCTURAL FEATURES AT THE SI/SIO2 INTERFACE
MATERIALS LETTERS
1987; 5 (3): 94-98
View details for Web of Science ID A1987G365300009
- Characterization of Defects in Materials edited by Siegel, R., W., Weertman, J., R., Sinclair, R. 1987
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INSITU HIGH-RESOLUTION ELECTRON-MICROSCOPY REACTIONS IN SEMICONDUCTORS
ULTRAMICROSCOPY
1987; 23 (3-4): 383-395
View details for Web of Science ID A1987L028100017
- Phase Equilibria in Metal-Gallium-Arsenic Systems: Thermodynamic Considerations for Metallization Materials J. Appl. Phys. 1987; 61: 2195-2202
- In Situ High Resolution Electron Microscopy for Interface Studies 1987
- Interfacial Reactions in Titanium-Silicon Multilayers 1987
- In Situ HREM of Interface Reactions in Semiconductors Ultramicroscopy 1987; 23: 383-396
- High-Resolution Electron Microscopy and Scanning Tunneling Microscopy of Native Oxides on Silicon Science 1987; 237: 630-633
- High-Resolution Electron Microscopy of Structural Features at the Si/SiO2 Interface MateR. Letts. 1987; 5: 94-98
- Kinetics & Oxide Composition for Thermal Oxidation of Cadmium Telluride J. Appl. Phys. 1987; 62: 1469-1476
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HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY OF SILICON REGROWTH AT CONTROLLED ELEVATED-TEMPERATURES
NATURE
1986; 322 (6079): 531-533
View details for Web of Science ID A1986D523100048
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PLASTIC-DEFORMATION OF WC-CO AT HIGH CONFINING PRESSURE
SCRIPTA METALLURGICA
1986; 20 (5): 701-705
View details for Web of Science ID A1986C225900022
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DEFORMATION ENHANCED DECARBURIZATION OF WC-CO
SCRIPTA METALLURGICA
1986; 20 (1): 55-60
View details for Web of Science ID A1986AYB8400011
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NEUTRON-DIFFRACTION AND EXAFS EVIDENCE FOR TIO5 UNITS IN VITREOUS K2O.TIO2.2SIO2
JOURNAL OF NON-CRYSTALLINE SOLIDS
1986; 79 (1-2): 117-136
View details for Web of Science ID A1986A257700009
- Crystalline-To-Amorphous Transitions in Ti-Ni Alloys 1986
- The Evolution of Si/SiO Interface Roughness edited by Huff, H., R., Abe, T., Kolbesen, B. 1986
- Electron Microscope in 1987 Yearbook of Science and Technology McGraw-Hill, New York. 1986: 173–176
- High Resolution Transmission Electron Microscope Observations of Silicon Regrowth at Controlled Elevated Temperatures Nature 1986; 322: 531-533
- Plastic Deformation of WC-Co at High Confining Pressure Scripta Met. 1986; 20: 701-705
- In Situ HREM and HVEM Studies of Silicon Epitaxial Regrowth 1986
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LATTICE IMAGES OF DEFECT-FREE SILICON ON SAPPHIRE PREPARED BY ION-IMPLANTATION
APPLIED PHYSICS LETTERS
1985; 47 (6): 626-628
View details for Web of Science ID A1985AQH1900032
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TERNARY PHASE-DIAGRAMS IN SEMICONDUCTOR SYSTEMS
MINERALS METALS MATERIALS SOC. 1985: A115–A115
View details for Web of Science ID A1985AVK1200930
- Characterization of Emitter-Collector Shorts by Anodization, Voltage Contrast SEM and TEM 1985
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THE B2 TO R TRANSFORMATION IN TI50NI47FE3 AND TI49.5NI50.5 ALLOYS
ACTA METALLURGICA
1985; 33 (9): 1717-1723
View details for Web of Science ID A1985APP5200015
- In-Situ High Resolution Transmission Electron Microscopy of Dynamic Events During the Amorphous to Crystalline Phase Transformation in Silicon 1985
- Morphological Studies of Polysilicon Emitter Contacts 1985
- Silicon on Sapphire of Single Crystal Quality Obtained by Double Solid Phase Expitaxial Regrowth 1985
- Precipitation of Phosphorus and Tin in Temper Embrittled Low Alloy Steel Scripta Met. 1985; 19: 111-116
- In Situ TEM Study of Martensitic NiTi Amorphization by Ni Ion Implantation Nucl. Instrum. Methods B 1985; 7/8: 20-25
- Direct Observation of Defect Motion in Silicon By High Resolution Transmission Electron Microscopy 1985
- Silicon Nitride Joining J. Am. Ceram. Soc. 1985; 68: 472-478
- Metastable Phase Formation in Titanium-Silicon Thin Films J. Appl. Phys. 1985; 57: 5240-5245
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DISPLACEMENT BOUNDARIES IN TINI ALLOYS
SCRIPTA METALLURGICA
1985; 19 (10): 1257-1259
View details for Web of Science ID A1985ASD6700027
- Lattice Images of Defect Free Silicon-On-Sapphire Prepared by Ion Implantation Appl. Phys. Lett. 1985; 47: 626-628
- Delineation of Emitter-Collector Shorts in Bipolar Test Structures by Voltage Contrast Scanning Electron Microscopy SEM 1985; III: 1047-1053
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MECHANICAL TWINNING IN TI50NI47FE3 AND TI49NI51 ALLOYS
ACTA METALLURGICA
1985; 33 (9): 1725-1733
View details for Web of Science ID A1985APP5200016
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DELINEATION OF EMITTER-COLLECTOR SHORTS IN BIPOLAR TEST STRUCTURES BY VOLTAGE CONTRAST SCANNING ELECTRON-MICROSCOPY
SCANNING ELECTRON MICROSCOPY
1985: 1047-1053
View details for Web of Science ID A1985ATA9300013
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INSITU TEM STUDY OF MARTENSITIC NITI AMORPHIZATION BY NI ION-IMPLANTATION
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
1985; 7-8 (MAR): 20-25
View details for Web of Science ID A1985AGM5800004
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METASTABLE PHASE FORMATION IN TITANIUM-SILICON THIN-FILMS
JOURNAL OF APPLIED PHYSICS
1985; 57 (12): 5240-5245
View details for Web of Science ID A1985AJN5500019
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PRECIPITATION OF PHOSPHORUS AND TIN IN TEMPER EMBRITTLED LOW-ALLOY STEEL
SCRIPTA METALLURGICA
1985; 19 (1): 111-116
View details for Web of Science ID A1985AAR4700022
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CADMIUM TELLURIDE FILMS AND SOLAR-CELLS
IEEE TRANSACTIONS ON ELECTRON DEVICES
1984; 31 (5): 528-538
View details for Web of Science ID A1984SQ49200003
- Thin Foil Artifacts Observed in Electron Diffraction on a TiNi Alloy Scripta Met. 1984; 18: 1143-1147
- Structural Determination of Amorphous Ti-Ni Alloys 1984
- Phase Equilibria in Thin-Film Metallizations J. Vac. Sci. Technol., 1984; B2: 781-784
- The Morphology of the Polysilicon-SiO2 Interface 1984
- High Resolution Electron Microscopy in Quantitative Electron Microscopy edited by Chapman, J., N., Craven, A., J. SUSSP Publications, Edinburgh. 1984: 341–350
- The Preparation of Cross-Section Specimens for Transmission Electron Microscopy J. Electron Microsc. Tech. 1984; 1: 53-61
- Cadmium Telluride Films and Solar Cells IEEE Trans. Electron Devices 1984; ED-31: 528-538
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THIN FOIL ARTIFACTS OBSERVED IN ELECTRON-DIFFRACTION ON A TI49.5NI50.5 ALLOY
SCRIPTA METALLURGICA
1984; 18 (10): 1143-1147
View details for Web of Science ID A1984TP01100023
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PHASE-EQUILIBRIA IN THIN-FILM METALLIZATIONS
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
1984; 2 (4): 781-784
View details for Web of Science ID A1984TV91800031
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DEFECT INTERACTIONS IN DEFORMED WC
ACTA METALLURGICA
1984; 32 (6): 941-947
View details for Web of Science ID A1984SX48200014
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INTERGRANULAR CRACKING IN WC-6-PERCENT CO - AN APPLICATION OF THE VONMISES CRITERION
ACTA METALLURGICA
1983; 31 (3): 373-378
View details for Web of Science ID A1983QF43300003
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HIGH-RESOLUTION ELECTRON-MICROSCOPY OF II-VI-COMPOUND SEMICONDUCTORS
INSTITUTE OF PHYSICS CONFERENCE SERIES
1983: 103-108
View details for Web of Science ID A1983TV60200016
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TRANSMISSION ELECTRON-MICROSCOPY OF ANNEALED ZRO2+8 MOL PERCENT SC2O3
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
1983; 66 (3): 213-216
View details for Web of Science ID A1983QG54000014
- Defect Structure of WC Deformed at Room and High Temperatures edited by Viswanathan, R., K., Rowcliffe, D., J., Gurland, J. 1983
- Transmission Electron Microscopy Studies of the Polycrystalline Silicon – SiO2 Interface Thin Solid Films 1983; 104: 153-161
- Lattice Imaging of CdS/CdTe Solar Cell Interface edited by Bailey, G., W. 1983
- HREM of Interfaces and Defects in Semiconductors 1983
- Detection of Thin Intergranular Cobalt Layers in WC-Co Composites by Lattice Imaging J. Am. Ceram. Soc. 1983; 66: C137-C139
- Observation of Dislocation Reactions in CdTe at Lattice Resolution 1983
- High Voltage High Resolution Electron Microscopy of Compound Semiconductors 1983
- Microstructural Characterization of Deformation and Precipitation in (W, Ti)C edited by Viswanathan, R., K., Rowcliffe, D., J., Gurland, J. 1983
- High Resolution Electron Microscopy II-VI Compound Semiconductors 1983
- Intergranular Cracking in WC-6%Co: An Application of the von Mises Criterion Acta Metall. 1983; 31: 373-378
- Transmission Electron Microscopy of Annealed ZrO2+8Mol%Sc2O3 J. Am. Ceram. Soc. 1983; 66: 213-217
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A MORPHOLOGICAL-STUDY OF PRE-MARTENSITIC EFFECTS IN TINI
ACTA METALLURGICA
1982; 30 (1): 109-123
View details for Web of Science ID A1982MX59800014
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HIGH-RESOLUTION LATTICE IMAGING OF CADMIUM TELLURIDE
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES
1982; 45 (4): 693-711
View details for Web of Science ID A1982NN06100010
- Lattice Resolution Movie of Defect Modification in Cadmium Telluride 1982
- The Effect of Oxygen in Cosputtered (Titanium + Silicon) Films edited by Corbett, J., W., Mahajan, S. 1982
- Applications of the 2 1/2 D TEM Technique 1982
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DYNAMIC OBSERVATION OF DEFECT ANNEALING IN CDTE AT LATTICE RESOLUTION
NATURE
1982; 298 (5870): 127-131
View details for Web of Science ID A1982NW89400030
- Dynamic Observation of Atomic-Level Events in Cadmium Telluride by High Resolution TEM edited by Corbett, J., W., Mahajan, S. 1982
- High Resolution Lattice Imaging of Cadmium Telluride Philos. Mag. 1982; A45: 693-711
- Characterization of the Lattice Displacement Waves in Premartensitic TiNi Acta Metall. 1982; 30: 125-138
- A Morphological Study of ’Premartensitic’ Effects in TiNi Acta Metall. 1982; 30: 109-123
- Electron Irradiation Induced Crystalline Amorphous Transitions in Ni-Ti Alloys Scripta Met. 1982; 15: 589-592
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MARTENSITIC TRANSFORMATIONS IN A TINI THIN FOIL
JOURNAL DE PHYSIQUE
1982; 43 (NC-4): 243-248
View details for Web of Science ID A1982QE67200033
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CHARACTERIZATION OF THE LATTICE DISPLACEMENT WAVES IN PRE-MARTENSITIC TINI
ACTA METALLURGICA
1982; 30 (1): 124-138
View details for Web of Science ID A1982MX59800015
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NATIVE TELLURIUM DIOXIDE LAYER ON CADMIUM TELLURIDE - A HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY
APPLIED PHYSICS LETTERS
1981; 39 (12): 951-953
View details for Web of Science ID A1981MU66000007
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THE EFFECT OF ORIENTATION, GRAIN-SIZE AND POLYMORPHISM ON MAGNETIC-PROPERTIES OF SPUTTERED CO-RE THIN-FILM MEDIA
IEEE TRANSACTIONS ON MAGNETICS
1981; 17 (6): 3187-3189
View details for Web of Science ID A1981MR51100208
- Room Temperature Deformation Mechanisms and the Defect Structure of Tungsten Carbide Acta Metall. 1981; 29: 1645-1654
- Metallurgical Applications of the 2 1/2 D TEM Technique Met. Trans. 1981; 12A: 1503-1512
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ATOMIC MOTION ON THE SURFACE OF A CADMIUM TELLURIDE SINGLE-CRYSTAL
NATURE
1981; 290 (5805): 386-388
View details for Web of Science ID A1981LJ03300032
- The Premartensitic State in TiNi 1981
- High Resolution Transmission Electron Microscopy of Semiconductor Materials 1981
- Imaging of Defects in Cadmium Telluride Using High Resolution Transmission Electron Microscopy edited by Narayan, J., Tan, T., Y. 1981
- Recent Developments in Lattice Imaging of Materials in Annual Reviews of Materials Science edited by Huggins, R., A. Annual Reviews, Inc., Palo Alto, California. 1981: 427–439
- Atomic Motion on the Surface of a Cadmium Telluride Single Crystal Nature 1981; 290: 386-388
- High Resolution Imaging of Semiconductor Interfaces 1981
- Native Tellurium Dioxide Layer on Cadmium Telluride: A High Resolution Electron Microscopy Study Appl. Phys. Lett. 1981; 39: 951-953
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METALLURGICAL APPLICATIONS OF THE 21/2D TEM TECHNIQUE
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
1981; 12 (8): 1503-1512
View details for Web of Science ID A1981ME37000017
- Chemical and Microstructural Analyses of Grain Boundaries in BaTiO-Based Dielectrics edited by Levinson, L., M. 1981
- The Effect of Orientation, Grain Size and Polymorphism on Magnetic Properties of Sputtered Co-Re Thin Film Media IEEE Trans. Magn 1981; MAG-17: 3187-3189
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ROOM-TEMPERATURE DEFORMATION MECHANISMS AND THE DEFECT STRUCTURE OF TUNGSTEN CARBIDE
ACTA METALLURGICA
1981; 29 (9): 1645-1654
View details for Web of Science ID A1981MB66500011
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THE STRUCTURE OF TINI MARTENSITE
ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE
1981; 37 (OCT): 1803-1807
View details for Web of Science ID A1981MN94300001
- Physical Properties of Ion-Implanted SEM-Annealed Silicon edited by White, C., W., Percey, P., S. 1980
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ABNORMAL GRAINS IN MA753
MINERALS METALS MATERIALS SOC. 1980: 11–11
View details for Web of Science ID A1980KU55600082
- Analytical Electron Microscopy of Ferroelectric BaTiO3 1980
- A Transmission Electron Microscopical Investigation of Phase Transformations in TiNi 1980
- Defect Structure of Deformed WC 1980
- Structure Imaging of Defects in Cadmium Telluride 1980
- Comments on ’The Early Stages of the Transformation in Dilute Alloys of Titanium in Nickel Scripta Met. 1980; 14: 373-376
- A Quantitative Assessment of the Capabilities of 2 1/2 D Microscopy for Analyzing Crystalline Solids Philos. Mag. 1980; A42: 691-704
- Combined High Resolution and Analytical TEM Studies of Phase-Separated Alloys 1980
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A QUANTITATIVE ASSESSMENT OF THE CAPABILITIES OF 21/2D MICROSCOPY FOR ANALYZING CRYSTALLINE SOLIDS
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES
1980; 42 (6): 691-704
View details for Web of Science ID A1980KZ26600001
- High Resolution Imaging of Cadmium Telluride 1980
- Microanalysis by Lattice Imaging in Analytical Electron Microscopy edited by Hren, J., J., Goldstein, J., I., Joy, D., C. Plenum Press, New York. 1979: 507–534
- Lattice Fringe Imaging of Alloys 1979
- Growth Relationships in NbSn-Cu Superconducting Composites edited by Kuhlman-Wilsdorf, D., Harrigan, W., C. 1979
- Origin of Stacking Faults in NiTi Martensite edited by Cowley, J., M., Cohen, J., B., Salamon, M., B. 1979
- In-Situ Observations of Diffusionless Transformations in NiTi 1979
- Determination of Local Composition by Lattice Imaging Met. Trans. 1978; 9A: 373-380
- Modulated Substitutional-Intersitial Solute-Atom Clustering in Nitrided Austenitic Fe-34 Ni-V Alloys 1978
- Applications of Lattice Fringe Imaging 1978
- Lattice Imaging and Optical Microanalysis of a Cu-Ni-Cr Spinodal Alloy Met. Trans. 1978; 9A: 381-387
- Aspects of Microanalysis in a TEM 1978
- Lattice Imaging Study of a Martensite-Austenite Interface Acta Metall. 1978; 26: 623-628
- Fine Structure of Interfaces as Revealed by Lattice Fringe Imaging 1977
- Structure of Ordered Alloys J. Phys. 1977; C7 (38): 165-171
- A Preliminary Lattice Image Investigation of Nickel-Titanium Martensite J. Phys. 1977; C7 (38): 453-456
- Lattice Image Studies of B19 Ordering and Interfacial Structures in Mg3Cd Acta Metall. 1977; 25: 235-249
- Direct Observation and Characterization of Lattice Defects in Materials in Treatise on Materials Science and Technology edited by McCrone, R., K. Academic Press, New York. 1977: 1–45
- The Importance of Electron Diffraction to Transmission Electron Imaging Trans. Am. Cryst. Soc. 1977; 13: 101-126
- Discussion of An Electron Diffraction Study of Short-Range Order in Quenched Ni4Mo Alloy Acta Metall. 1977; 25: 101-126
- Preliminary Observations of Electron Irradiation Damage in Short-Range Ordered Ni4Mo 1976
- Applications of High Resolution Electron Microscopy in Materials Science Report of Workshop on High Resolution Electron Microscopy edited by Thomas, G., Glaeser, R., M., Cowley, J., M. Lawrence Berkeley Laboratory Special Publication. 1976: 71–79
- Applications of High Resolution Electron Microscopy in Materials Science edited by Thomas, G., Glaeser, R., M., Cowley, J., M. 1976
- Optical Diffraction from Lattice Images of Alloys Acta Metall. 1976; 24: 789-795
- Applications of High Resolution Electron Microscopy in Materials Science edited by Thomas, G., Glaeser, R., M., Cowley, J., M. 1976
- Lattice Image and Optical Diffraction Studies of Alloys 1976
- Optical Microdiffraction in Lattice Image Analysis 1976
- Observations of B19 Order ing in Mg3Cd Thin Foils Scripta Met. 1976; 10: 489-493
- Analysis of Ordering in Cu3Au, Utilizing Lattice Imaging Techniques Acta Metall. 1975; 23: 873-883
- Studies of Atomic Scattering Factors from the Critical Voltage in Ordered Alloys: Applications to Cu3Au 1975
- Lattice Image Studies of Ordered Alloys 1975
- On the Lattice Parameter of Non-Random Solid Solutions Philos. Mag. 1975; 31: 697-712
- Antiphase Domains and Diffraction Spot Splitting in Cu3Au J. Appl. Crystallography 1975; 8: 206-211
- Lattice Imaging of Spinodal Alloys 1975
- Applications of the Critical Voltage Effect for the Study of Ordering Philos. Mag. 1975; 32: 501-512
- Lattice Image Contrast of Ordered Domains in CuAu 1974
- Spinodal Decomposition of a Nickel-Titanium Alloy Phys. Status Solidi A 1974; 26: 285-298
- Lattice Imaging of Ordered Alloys 1974
- A New 1000C Double Tilt Stage for the Hitachi 650 kV Microscope 1974
- High Resolution Transmission Electron Microscopy 1973
- Measurement of Relative Bond Energies in Some Ordered Nickel-Based Alloys by Field-Ion Microscopy Phys. Status Solidi A 1973; 16: 469-484
- On the Determination of a Local Order Parameter in a Nickel-Titanium Alloy Philos. Mag. 1973; 28: 1111-1123