Defects in heterogeneous solids - from microphysics to macrophysics

Abstract

This series of conferences has focused primarily on the atomic and electronic structure of defects. This talk highlights another major area, namely the role of defects in determining the behavior of materials at intermediate or mesoscopic length scales. For example, in polycrystals, vacancy diffusion mediates extensive rearrangements at mesoscopic length scales, e.g. void growth, grain boundary migration, dislocation climb. A systematic approach is outlined that leads to a derivation of rigorous mesoscopic equations from first principles and sets the stage for first-principles mesoscopic calculations of material properties. Results of void growth and void shape evolution in polycrystals in the presence of electrical current are used to illustrate the general approach.