Influence of cation substitution on the polymorphic transformation in Ag2–хCuхS (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 Ag 2–х Cu х S (х = 0.45, 0.8, and 1.07) solid solutions on the temperature of polymorphic phase transitions is demonstrated. The phase composition of Ag 2–х Cu х S (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 Ag 0.93 Cu 1.07 S 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 (Ag 1.55 Cu 0.45 S and Ag 1.2 Cu 0.8 S) and the phase transitions temperatures differ from the structure and corresponding parameters of AgCuS single crystal.