Nonempirical Calculation of Ill–V Ternary Semiconductor Phase Diagrams

Nonempirical calculation of a phase diagram for the III-V ternary semiconductor is attempted. The atomic interaction energies are obtained based on the results of pseudopotential perturbation calculation, while the entropy term is evaluated by the tetrahedron approximation of the cluster variation method. Phase diagrams of pseudobinary GaSb–In–Sb and GaP–LnP are obtained, and both are characterized as the phase separation type. The origin of the asymmetry of the solubility line is discussed.