Simulations of extreme conditions:
From tribology to optoelectronic materials

Dr. Martin H. Müser, Assoc. Prof
Department of Applied Mathematics
University of Western Ontario
London, Ontario, CANADA

Abstract
In my talk, I will discuss two examples, which demonstrate how computer simulations guide the understanding of materials and thereby assist the optimization of technical applications. The first example is concerned with mechanical contacts between two solids that have surfaces with self-affine topographies. Multi-scale simulations techniques were developed which made possible the calculation of the pressure distributions in these systems.  These in turn were required to model chemical processes at the molecular scale. One result of practical importance is that molecules, which crosslink under pressure, form protective films on surfaces.

The second example demonstrates the relevance of pressure-induced transitions in opto-electronic materials. Their functionality is based on the strong contrast of their properties between their crystalline and amorphous state.  A recently proposed reason for this contrast is the difference in the local order in the two phases. Simulations of the commercially used alloys confirm this hypothesis and demonstrate in addition that the materials cannot only be switched thermally but also with pressures and tensile loads opening a pathway to "cool" memory.

Thursday, March 20th
337 Towne Bldg.
2:00 – 3:00 p.m.