PHASE DIAGRAM OF THE SnSb2Te4–SnBi2Te4 SYSTEM AND SOME PROPERTIES OF THE SnSb2-xBixTe4 SOLID SOLUTIONS

Using differential thermal analysis and X-ray diffraction technique phase equilibria in the SnSb2Te4–SnBi2Te4 system were investigated and its T–x diagram was constructed. The system is non-quasibinary due to the incongruent melting of the starting ternary compounds, but it is stable below solidus. The system characterized by a continuous series of substitutional solid solutions with tetradimite-like hexagonal structure. The crystal lattice parameters are a linear function of the composition. Liquidus consists of one curve corresponding to the primary crystallization of solid solutions based on the SnTe compound (α-phase), which interacts with the liquid phase by peritectic reaction (L+ α↔γ) and forms solid solutions based on the SnSb2Te4 and SnBi2Te4 compounds. According to the results of powder diffraction patterns, the lattice parameters are determined. It was established that the crystal lattice parameters of solid solutions vary linearly with composition