The energetics of the misfit dislocations at the interface between a semi-infinite substrate and an epitaxial layer were studied by using a two-dimensional elastic lattice model. The model included not only the elastic deformation, but also the effect of a spontaneous force. The elastic energy of a system with a regular array of misfit dislocations at the interface was calculated by using an elastic lattice Green’s function. For a small positive misfit, the optimum dislocation period of the lattice model agreed with that given by continuum elasticity theory and was insensitive to the core structure. For a large misfit, an additional force distribution at the core had a marked effect. With a positive misfit, the system had a compressive force distribution at the core, and the optimum dislocation period of the lattice model was larger than that of continuum elasticity theory. The result was in agreement with experiment.

The Core Effect of Misfit Dislocations in Heteroepitaxy. H.Katsuno, M.Uwaha, Y.Saito: Journal of Crystal Growth, 2008, 310[7-9], 1380-4