Model of Surface Instabilities Induced by Stress

Abstract

We propose a model based on a Ginzburg-Landau approach to study a strain relief mechanism at a free interface of a nonhydrostatically stressed solid, commonly observed in thin-film growth. The evolving instability, known as the Grinfeld instability, is studied numerically in two and three dimensions. Inherent in the description is the proper treatment of nonlinearities. We find that these nonlinearities can lead to competitive coarsening of interfacial structures, corresponding to different wave numbers, as strain is relieved. We suggest ways to experimentally measure this coarsening.