The elastic energy of a heterostructure which consisted of materials having differing elastic moduli was calculated. An analytical solution for the elastic field of a periodic arrangement of screw misfit dislocations was obtained within the framework of the continuous theory of elasticity. This solution permitted the calculation of the critical thickness of the epitaxial layer and the analysis of its dependence upon the elastic contrast between the substrate and the epilayer. An analysis of the total elastic energy of the heterostructure showed that a transition from a pseudomorphic state, to a state with misfit dislocations, occurred in a similar manner to a first-order or second-order phase transition. The type of transition which the system underwent depended upon the relationship between the elastic moduli of the substrate and epilayer.

Misfit Dislocations in Epitaxial Heterostructures with Different Elastic Constants of the Substrate and Epitaxial Layer. E.Vigueras, E.Feldman, V.Yurchenko, L.Gumen, A.Krokhin: Philosophical Magazine A, 2001, 81[3], 667-81