Chapter 5 - Submolecular Regular Solutions

Abstract

This chapter introduces the quaternary submolecular regular solutions in which two sublattices are mixed. Such solutions include bonds corresponding to four binary constituent compounds. Baker’s approach of the cluster variation method was modified to apply to these solutions. The different approximations of this approach are used to consider such regular solutions. The miscibility gap of the solutions also depends on the free energies of the constituent compounds. The spinodal decomposition range is described, taking into account the coherency strain energy. The concentrations of pairs of the nearest neighbors (short-range order) are considered in several approximations of the cluster variation method. It is shown that self-assembling of identical clusters in some semiconductor alloys is preferential from the thermodynamics standpoint.