Influence of cation substitution on the polymorphic transformation in Ag2–х Cu х S (х = 0.45, 0.8, and 1.07) crystals

The influence of the concentration substitution of Ag ions for Cu ions in the structure of Ag2–хCuхS (х = 0.45, 0.8, and 1.07) solid solutions on the temperature of polymorphic phase transitions is demonstrated. The phase composition of Ag2–хCuхS (х = 0.45, 0.8, and 1.07) solid solutions has been investigated by X-ray diffraction at different temperatures. It is shown that the structure of the polymorphic modification of Ag0.93Cu1.07S composition and the phase transition temperature correspond to the structure and parameters of AgCuS single crystal. The structures of the modifications of compositions with a high silver concentration (Ag1.55Cu0.45S and Ag1.2Cu0.8S) and the phase transitions temperatures differ from the structure and corresponding parameters of AgCuS single crystal.