Leora is an Assistant Professor in the Department of Materials Science & Engineering, with a courtesy appointment in Mechanical Engineering, a term appointment in Photon Science at the SLAC National Accelerator Lab, and an appointment as a Precourt Center Fellow. Before coming to Stanford, Leora was a Lawrence Fellow in the Physics Division of the Physics and Life Sciences Directorate at Lawrence Livermore National Labs, where she developed the tools to study time-resolved defect dynamics in bulk materials -- giving new insights into long-standing problems in materials science. She led a large collaboration towards these goals and was involved in many projects that used dark-field X-ray microscopy and other tools to study dislocation patterning, recovery in metals, ultrahigh strength materials, radiation damage, automation and shape recognition methods. Leora did her PhD in Physical Chemistry with Prof. Keith Nelson at MIT, where she demonstrated how shock waves initiate chemistry in RDX that couples to deformations in unique ways that enhance the sensitivity. During that work, she also developing the ultrafast microscope for the study, which took movies with 300 billion frames per second of how quasi-2D shock waves converge, and adapted computer vision methods to quantify the imaging results. Leora did her BA and MSc in Chemistry at the University of Pennsylvania.
Assistant Professor, Materials Science and Engineering
Gabilan Fellow, Stanford University (2021 - Present)
Terman Fellow, School of Engineering, Stanford (2021 - Present)
Courtesy Appointment, Mechanical Engineering, Stanford (2021 - Present)
Precourt Center Fellow, Precourt Center for Renewable Energy, Stanford (2021 - Present)
Term Appointment, Photon Science, SLAC (2021 - Present)
Current Research and Scholarly Interests
My group develops new optical and analytical tools to reveal how imperfections deep inside materials instigate the dynamics that transform them. Spanning length- and time-scales from bonds breaking at single atoms through fracture or fatigue in macroscopic materials, these defect dynamics define complex high-dimensional problems that are difficult to reconcile at intermediate scales in order to predict or understand a material's behavior. To address this challenge, my group develops new types of time-resolved experiments aimed at the elusive "mesoscale" to directly visualize how large populations of subsurface defects drive them. With these new approaches, we tackle fundamental studies of how temperature drives materials, and more applied problems that connect our new insights to structural materials, manufacturing, energy science, and beyond.
In situ visualization of long-range defect interactions at the edge of melting.
2021; 7 (29)
Connecting a bulk material's microscopic defects to its macroscopic properties is an age-old problem in materials science. Long-range interactions between dislocations (line defects) are known to play a key role in how materials deform or melt, but we lack the tools to connect these dynamics to the macroscopic properties. We introduce time-resolved dark-field x-ray microscopy to directly visualize how dislocations move and interact over hundreds of micrometers deep inside bulk aluminum. With real-time movies, we reveal the thermally activated motion and interactions of dislocations that comprise a boundary and show how weakened binding forces destabilize the structure at 99% of the melting temperature. Connecting dynamics of the microstructure to its stability, we provide important opportunities to guide and validate multiscale models that are yet untested.
View details for DOI 10.1126/sciadv.abe8311
View details for PubMedID 34261647