The elastic energy of a heterostructure which consisted of materials having differing elastic moduli was calculated. By using the continuous theory of elasticity, an analytical solution was obtained for the elastic field of a periodic arrangement of screw misfit dislocations. This solution permitted the calculation of the critical thickness of the epilayer and the analysis of its dependence upon the elastic difference 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 manner which resembled 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 the 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