Stand-off positions and nonuniform distributions of misfit dislocations in heterophase systems

Abstract

Peculiarities in the spatial distribution of misfit dislocations near the interfaces in heterophase materials are discussed. The peculiarities include the shift of misfit dislocations to the stand-off position at the interface, formation of nonuniform misfit dislocation distributions along the interface, and temporal and spatial oscillations in defect densities in the material near the interface. Energetic, dynamic, and kinetic reasons leading to the above-mentioned effects are considered. The developed approach allows to find stand-off positions of misfit dislocations which are in good agreement with experiments and to determine critical misfit strain and thickness of the film corresponding to the transition between uniform and nonuniform dislocation distributions.