Graduate Seminar Series
February 24, 2023
10:00 a.m. ET
7500 Wean Hall
Investigating the role of localized structural effects on emerging properties in high entropy materials
Many properties we observe in materials are a direct consequence of their composition and local structure. High entropy materials are a unique class of systems that do not have a primary composition; rather they contain a near-equimolar distribution of several elements— where no single element serves as host. Such compositional disorder is accompanied by a unique distribution of localized structural distortions that can have a profound effect on properties such as thermal conductivity, magnetic interaction, diffusion, and more. A key point of interest in these materials is the implied breadth of property tunibility, which ranges in compositionally dependent functionalities from amorphous-like thermal conductivities to exotic magnetic states. In this talk, we present and discuss ongoing work on the local characterization of several high entropy compositions exhibiting crystal structures from rocksalts and spinels, to perovskites and Kagome lattices. In particular, the use of X-ray absorption fine structure (XAFS) is demonstrated to aid in understanding such disorder on the local level and how it may influence functional properties.
Dr. Christina Rost, Assistant Professor of Physics, James Madison University
Dr. Rost graduated with a Ph.D. in Materials Science and Engineering from North Carolina State University in 2016, following both a B.S. and an M.S. in Physics from Indiana University of Pennsylvania. Her Ph.D. focused on the development and phase-characterization of a novel class of oxide systems stabilized through configurational disorder, named “Entropy Stabilized Oxides”. After graduation, Tina was Postdoctoral Research Associate in the Experiments and Simulations in Thermal Engineering (ExSITE) group, within the Department of Mechanical and Aerospace Engineering at the University of Virginia. There, her work focused on experimental methods to test thermal properties at extremely high temperatures and thermal transport in complex and high-entropy oxides and carbides. Currently, her all-undergraduate research group at JMU focuses efforts on complex oxide synthesis and characterization. She is an active member of the American Ceramics Society and the American Physical Society.