QUASIBINAR SECTION OF AgGaS2-AgSbS2

The aim of this work is to study phase equilibrium and build a state diagram of the AgGaS2-AgSbS2 system. For research, the initial sulfides (AgGaS2 and AgSbS2) were synthesized from elements of high purity in quartz ampoules evacuated to 0.133 Pa. Quaternary alloys of the AgGaS2 – AgSbS2 systems were synthesized from ligatures at a temperature of 800–1300 K, depending on the composition. To homogenize the alloys, annealing was performed at 50–60 K below solidus for 300 h. Using complex methods of physicochemical analysis (differential thermal, X-ray phase, microstructural, microhardness measurement and density determination), phase equilibria in the AgGaS2-AgSbS2 system were studied. It was established that the AgGaS2-AgSbS2 system is a quasibinary section of the eutectic type and its state diagram is constructed. The coordinates of the eutectic correspond to 65 mol. % AgSbS2 and a temperature of 750 K. Based on the starting components in the section, the regions of solid solutions were determined. At room temperature, the regions of solid solutions based on AgGaS2 (8 mol. % AgSbS2) and based on AgSbS2 (14 mol. % AgGaS2) were revealed. At a eutectic temperature, solubility reaches 20 and 25 mol. %, respectively. According to the XRD data, α-solid solutions belong to monoclinic syngony, and with an increase in the concentration of AgGaS2, the lattice parameter increases (a = 12.861-12.972; b = 4.409-4.474; c = 13.282-13.324Å). AgSbS2 triple sulfide solid solutions crystallize in monoclinic syngony. These solid solutions are of the type of substitution. For structural and optical measurements, technological conditions for the growth of crystals of solid solutions were developed and their single crystals were grown. Single crystals of (AgSbS2)1-x(AgGaS2)x solid solutions were obtained by the Bridgman-Stockbarger method.