Effect of Interface on the Spinodal Decomposition of GaInPAs Solid Solutions during Liquid Phase Heteroepitaxy

The area of thermodynamical instability in non-ideal solutions appears below a critical temperature. On exceeding this temperature, the excessive energy of the solution takes positive values. It means that the repulsive forces acting between solution elements begin to dominate which leads to the spinodal decomposition. In the present paper, the effect of interatomic interactions on the limits of spinodal decomposition of substitutional solutions of Ga-In-P-As compounds was examined. The influence of the interface energy on the nature of spinodal decomposition was also analysed within the approximation of the coherent coupling of phases during heteroepitaxy from the liquid phase. It was demonstrated that the energy of elastic deformation of the interface lattice markedly changed conditions of the thermodynamical equilibrium.