Forces acting on misfit dislocations during interdiffusion

Abstract

The behaviour of misfit dislocations introduced to accommodate differences in lattice parameter at the interface between two epitaxially oriented crystals of different materials is studied as a function of the degree of interdiffusion of the constituents. The forces considered to be acting on the dislocations are the elastic interaction force between misfit dislocations, the homogeneous force arising from the difference in atomic volume of the constituents, and the osmotic force produced by the net vacancy flux accompanying interdiffusion. In the elasticity calculations, image forces and end effects, including buckling terms, are analysed. The results are compared with prior treatments of related problems, all of which have involved different boundary conditions, and none of which has included considerations if the osmotic force together with the other forces.