Phase equilibria of the SnTe–Sb2Te3–Te portion of the Sn–Sb–Te ternary system have been experimentally investigated using differential thermal analysis (DTA), powder X-ray diffraction (XRD), and microstructural analysis methods. Based on the measured experimental results and literature information, isothermal sections at 500 K, liquidus surface projection, and several vertical sections of the phase diagram were plotted. The 500 K phase diagram of this system consists of 2 single-phase regions, 2 two-phase regions, and 3 three-phase regions. The liquidus surface projection is represented by the primary crystallization fields of 5 phases. The primary crystallization fields of all phases, the types, and coordinates of non- and monovariant equilibria were determined. Obtained experimental data can be valuable input for design for Sn–Sb–Te-based alloys

The SnTe–Sb2Te3–Te system was studied in the temperature range 300–400 K by X-ray powder diffraction and EMF measurements of (–) SnTe(s.)|liquid electrolyte, Sn2+|(Sn–Sb–Te) (s) (+) reversible concentration cells. An equilibrium solid phase diagram of the system was constructed. All telluride phases of the system, namely, ternary compounds SnSb2Te4 and SnSb4Te7 and SnTe-base (α) and Sb2Te3-base (β) solid solutions, were found to be tie-lined with tellurium. Equations for temperature-dependent EMF in β + Те, β + SnSb4Te7 + Те, SnSb4Te7 + SnSb2Te4 + Те, α + SnSb2Te4 + Те, and α + Те heterogeneous phase fields were derived from EMF measurements, and were used to calculate the partial thermodynamic functions of SnTe in alloys. The thus-obtained data combined with the SnTe thermodynamic functions were used to calculate the partial molar functions of tin in alloys. The thus-obtained values and the equilibrium solid phase diagram of the SnTe–Sb2Te3–Te system, together with the relevant thermodynamic functions of Sb2Te3, were used to calculate the standard Gibbs free energies of formation and enthalpies of formation and the standard entropies of formation for SnSb2Te4, SnSb4Te7, and Sb2Te3- and SnTe-base solid solutions.

The boundaries of stable and metastable states of solid solutions of the MnTe-Sb2Te3 and SnTe-Sb2Te3 systems were determined by solving the thermodynamic equations of phase equilibria using the multipurpose genetic algorithm (MGA). As initial information, we used a small amount of experimental data from DTA and X-ray diffraction analysis, and thermodynamic functions of formation of MnTe, SnTe, Sb2Te3, MnSb2Te4, MnSb4Te7 SnSb2Te4, and SnSb4Sb7 compounds. The temperature-concentration dependences of the Gibbs energy of the formation of solid solutions from binary compounds, as well as from simple substances in quasi-binary sections, were determined using a subregular model of solutions of nonmolecular compounds as applied to telluride systems. The coordinates of the boundaries of metastable and stable solid solutions, in contrast to the entropy, are not very sensitive to the error in determining the enthalpy of formation of binary and ternary tellurides of manganese, tin, and antimony. It was revealed that the boundaries of β (Sb2Te3) solid solutions in MnTe-Sb2Te3 system extend to 10 mol

Using differential thermal analysis and X-ray diffraction technique phase equilibria in the SnSb 2 Te 4 -SnBi 2 Te 4 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 SnSb 2 Te 4 and SnBi 2 Te 4 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.

The SnTe–Sb2Te3–Te system has been studied in the temperature range 300–430 K using emf measurements on reversible concentration cells of the type (–)SnTe(s) | liquid electrolyte, Sn2+ |(Sn–Sb–Te)(s)(+). The system has been shown to consist of two three-phase regions, separated by the SnSb2Te4–Te tie line. The best fit equation for the temperature-dependent emf data has been used to evaluate the partial thermodynamic functions of the SnTe and Sn in the alloys. Using these data, subsolidus phase diagram data for the SnTe–Sb2Te3–Te system, and relevant thermodynamic functions for SnTe and Sb2Te3, we calculated the standard Gibbs energy of formation, standard enthalpy of formation, and standard entropy of the SnSb2Te4 compound.