PHYSICOCHEMICAL AND X-RAY DIFFRACTION STUDY OF PHASE FORMATION IN THE InSe-SrSe SYSTEM AND STUDY OF ELECTROPHYSICAL PROPERTIES OF SOLID SOLUTION ALLOYS

Abstract

Using the methods of physicochemical analysis (DTA, X-ray diffraction, MSA, as well as density and microhardness measurements), phase formation in the InSe-SrSe system was studied and its phase diagram was constructed. It was found that the InSe-SrSe system is a quasi-binary section of the ternary system Sr-In-Se and is eutectic. A ternary compound of the formula SrInSe₂ is formed in the system with a component ratio of 1:1. The SrInSe₂ compound melts congruently at 1180°C. According to the results of X-ray structural analysis, it was established that the SrInSe₂ compound crystallizes in the orthorhombic syngony, the lattice parameters are:  a = 10.95 Å; b = 8.65 Å; c = 8.42 Å. The coordinates and temperatures of the two eutectics formed in the system are 15 and 65 mol % SrSe and t = 847 K and t = 1273 K, respectively. In the system at room temperature based on the InSe compound, solid solutions reach up to 5 mol % SrSe, and on it SrSe up to -3 mol % InSe. As a result of studying the electrical conductivity (σ), thermal conductivity (α), current (I) and specific resistance (ρ) of solid solution alloys (InSe)_1-x(SrSe)_x (x=0.01; 0.02; 0.03; 0.05), it was established that solid solution alloys are semiconductors with medium resistance.