Heat Capacity and Lattice Anharmonicity in Cu‐III‐VI2 Chalcopyrite Compounds

Abstract
The molar heat capacity at constant pressure is measured for CuGaS2 in the temperature range from 300 to 600 K and for CuGaTe2, CuInS2, CuInSe2, and CuInTe2 from 300 to 500 K with an estimated accuracy of ±1 J/mol K. The anharmonic contributions to the heat capacity at constant pressure and at constant volume are estimated and analysed in terms of perturbation theory. The volume Grüneisen functions of the compounds are evaluated and compared with existing literature data.