Structural Changes and Mass Transfer in Elastically Strained Films

Abstract

Elastic strains influence structural changes in solids. One example of such an influence is the growth of grains of defined orientation during deformational annealing of polycrystalline specimens [1, 2]. Analogous effects can also be observed in thin-film structures. Ievlev at al. [3] discuss elastic interaction of the film with the substrate during heteroepitaxy. They note that in certain cases the film growth in a nonepitaxial orientation can be caused by minimization of the elastic free energy of the film—substrate system. The elastic energy depends on crystallite orientation, in this case due to the anisotropy of the elastic properties of the film and substrate. Anisotropic strains of various nature also apparently play a substantial role where oriented films form on disoriented substrates [4]. Crystallites with preferred orientation on the substrate and their preferred growth can be explained on the basis of the conditions for minimal elastic energy.