Synthesis and X-ray Powder Diffraction Study of Alloys in the As2Se3-InSe System

Abstract

Phase equilibria in the As2Se3–InSe system were studied by physicochemical analysis methods (differential thermal, X-ray powder diffraction, and microstructural analyses and microhardness and density measurements), and the phase diagram of the system was constructed. It was found that the system is a quasi-binary section of the ternary system In–As–Se and is characterized by the formation of two ternary selenides, InAs2Se4 and In3As2Se6, melting without decomposition at 775 and 810°C, respectively. The coordinates of eutectic points are (13 mol % InSe, 315°C), (80 mol % InSe, 675°C), and (85 mol % InSe, 535°C). The arsenic selenide-based glass-forming range is 20 mol % InSe, and the crystalline-glass range extends to 35 mol % InSe. The solubilities based on As2Se3 and InSe are limited and are 5 and 3 mol %, respectively. According to X-ray powder diffraction analysis data, the compounds InAs2Se4 and In3As2Se6 crystallize in the tetragonal system with the unit cell parameters a = 9.44 A, c = 8.73 A, V = 785.6 A3, Z = 4 and a = 9.42 A, c = 8.77 A, Z = 3, respectively.