Speaker: Jessica Krogstad, Assistant Professor, Materials Science and Engineering University of Illinois, Urbana-Champaign
Title: Exploring the Potential of Concentrated Point Defects: Their Role in Mass Transport, Microstructural Evolution and Material Functionality
Abstract: 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.