Looking beyond phase transitions: controlling chemical bonds, disorders and defects with mechanical pressure

Date and Time: 
Fri, 09/25/2020 - 2:00pm
Speaker: 
Hao Yan
Job title: 
Assistant Professor
Affiliation: 
Department of Chemistry, University of North Texas
Abstract: 

Matters under high mechanical pressure is traditionally the research realm of geology and condensed matter physics. In bulk homogeneous solids pressure leads to diminishing interatomic distance and phase transitions. On the other hand, the effect of pressure is much more complicated and less understood in molecular, low-dimensional and disordered systems. Here pressure give rise to highly localized and anisotropic interactions, offering a unique platform to control material properties and reactions at the level of individual atoms and bonds. In this talk I will discuss our recent findings in this direction, from mechanical activation of dinitrogen and C-H bonds to pressure-modulated diffusion and defect formation in disordered and nanostructured solids. These findings provide a first glance into a new frontier for chemistry and materials discovery that is inaccessible through ambient conditions.

Biography: 

Dr. Hao Yan is an assistant professor of chemistry at UNT. He obtained his Ph.D. in 2010 from Harvard under the advisory of Charles Lieber. He worked at Stanford University and SLAC national laboratory as a postdoctoral researcher and staff scientist before joining the faculty of UNT in fall 2019. His research group works at the intersection of chemistry, materials science and mechanical science, with a broad focus on understanding chemistry in extreme environments.