MSE Seminar Series: Exploring the potential of concentrated point defects
Full Title: Exploring the potential of concentrated point defects: Their role in mass transport, microstructural evolution and material functionality
Speaker: Jessica Krogstad, Assistant Professor, Dept of Materials Science and Engineering at
University of Illinois, Urabana-Champaign
Point defects are ubiquitous within materials. In many cases these defects contribute to useful material functionality but in excess they can also lead to degradation. Here we present several vignettes in which concentrated populations of point defects interact with microstructural features resulting in new perspectives on phase transformations and diffusion kinetics. We will approach this discussion from two angles: material systems wherein the excessive point defect population predominantly arises through materials synthesis choices and the other in which point defects are introduced via bombardment of an already crystalline system. In the former, the evolution of defects are driven by both intrinsic materials properties such as the stacking fault energy and extrinsic parameters such as substrate temperature and plasma energy. In the later, the crystalline lattice must respond and adapt to the flux of defects. However, in both cases, when the resulting nonequilibrium materials are allowed to relax, they do so in unexpected ways. We will present these observation as well as the broader potential of nonequilibrium point defect populations in understanding microstructural evolution, mass transport and material functionality.
Jessica A. Krogstad is an assistant professor in the Department of Material Science and Engineering at the University of Illinois, Urbana-Champaign. She received her PhD in Materials at the University of California, Santa Barbara working with Prof. Carlos G. Levi and completed a postdoctoral at Johns Hopkins University with Prof. Kevin J. Hemker before joining UIUC in 2014. Her current research explores the interplay between phase or morphological evolution and material functionality in structural materials under extreme conditions. She is the recipient of a several awards including DOE Early Career Award, the ACerS Robert L. Coble Award for Young Scholars and the TMS Early Career Faculty Fellow Award.