Peculiarities of phonon spectra and anomalies of the temperature dependencies of heat capacities of A3B5 compounds and their mutual solid solutions

The temperature dependencies of the heat capacity and thermal expansion of gallium arsenide, indium arsenide, indium phosphide, and (GaAs)0.2(InAs)0.8 solid solutions were analyzed by Einstein-Debye approximation. A simple model of the phonon spectrum of the substances is suggested. This model allowed us to establish the causes of the anomalous behavior of the thermal characteristics of the substances at low temperature.