Phase Equilibria in the Ag2Te-SnTe-Sb2Te3 System and Thermodynamic Properties of the (2SnTe)1−x (AgSbTe2) x Solid Solution

Abstract

Phase equilibria in the Ag2Te-SnTe-Sb2Te3 system were experimentally investigated by means of differential thermal analysis, powder x-ray diffraction techniques, microhardness and electromotive force measurements (EMF) of concentration chains with Ag4RbI5 solid electrolyte. A liquidus surface projection of the system, 700 and 400 K isothermal sections, as well as four vertical sections of the phase diagram were constructed. The primary crystallization fields of phases and homogeneity range of phases were also determined. The character and temperature of the various non- and monovariant equilibria were identified. The system includes a high-temperature cubic structured solid solution along the SnTe-“AgSbTe2” section, which partially (0-15 mol.% SnTe) decompose below 630 K. The partial molar thermodynamic functions of silver in alloys and standard integral thermodynamic functions of the (2SnTe)1−x (AgSbTe2) x (where x = 0.1; 0.2; 0.4; 0.6 and 0.8) solid solution were calculated based on the EMF measurements results.