Phillip Geissler

Professor Phillip Geissler, University of California, Berkeley. "Nanocrystals in flux: The importance of geometry during structural and compositional change." Woodward CCB Departmental Colloquium.

The repertoire of experimentally accessible nanostructures is greatly expanded by abilities to modify their shape and composition post-synthesis. Procedures for doing so, however, are typically far from equilibrium, and therefore difficult to control. Here I will discuss theoretical and computational work to understand the microscopic dynamics of two such processes: (i) chemical etching, which triggers a driving-force dependent sequence of shape changes, and (ii) cation exchange, which swaps out chemical constituents in situ. In both cases geometry plays a surprisingly dominant role in determining the nonequilibrium fate of model systems, even at the atomic scale.