Specific Heat of Superionic Conductor Ag₂S, Ag₂Se and Ag₂Te in α-Phase

Specific heat capacities of “superionic conductor”, Ag chalcogenides have been measured for Ag 2 S, Ag 2 Se and Ag 2 Te in the temperature range, 120–520 K. In every case, the heat capacity at constant pressure, C p decreases with increasing temperature over the fairly wide range above transition temperature. The behavior of the excess specific heat capacity can be explained fairly well as the transition of Ag + ions between two or more types of sites in the average structure, by a quasi-chemical method, applied to the theory of order-disorder transformations.