The lattice heat capacity of binary compounds in the approximation of three-dimensional debye sublattices

An analytic description of the temperature dependence of the heat capacity of crystals in the model of interacting three-dimensional Debye sublattices is suggested. The parameters of the model are the characteristic temperatures Θ2 and Θ3 of the sublattices and temperature Θ1 determined by the interaction between the sublattices. Satisfactory applicability of the model is substantiated for the examples of the temperature dependences of the heat capacity of gallium and indium arsenide solid solutions.