Internal strain energy of ternary solid solutions of cubic modification

Abstract

The crystal structure of the ternary solid solutions , and is described theoretically on the microscopic level, and the energies of internal strain in these solutions are calculated in terms of the valence-force-field model. For the solid solutions and the internal strain energy is an important parameter inasmuch as it is responsible for the existence of a broad miscibility gap in which solid solution formation is possible under thermodynamically nonequilibrium conditions. At the same time the miscibility gap does not present any serious problem for the solid solutions. In view of the tendency for spinodal decomposition, common for these materials, the and solid solutions can also be synthesized over a wide range of compositions under thermodynamically nonequilibrium conditions that ensure formation of metastable single-phase solid solutions. Formation of and solid solutions with x = 0.25, 0.50 and 0.75 as superstructures immediately in the course of their synthesis is the most likely event.