Phase Equilibria in the AgGeSe–AgGeSeI–GeSe System

Phase equilibria in the AgGeSe–AgGeSeI–GeSe (A) system were studied using differential thermal analysis and X-ray diffraction technique. The diagrams of the AgGeSe–AgGeSeI and AgGeSeI–GeSe boundary components, the liquidus surface projection, the isothermal section at 300 K, and some polythermal sections of the phase diagram of system A were constructed. It was established that the boundary system AgGeSe–AgGeSeI is characterized by the formation of a continuous series of solid solutions between AgGeSeI and the high-temperature cubic modification of the AgGeSe, as well as limited solid solutions based on the low-temperature modification of the latter. The formation of solid solutions leads to a decrease in the polymorphic transition temperature of the AgGeSe and stabilization of the high-temperature cubic phase at room temperature.