A simple thermodynamic description of the combined Einstein and elastic models

Abstract

A simple application of the Einstein model combined with an elastic description of the solidstate is developed. The frequency of quantum oscillators has been assumed as volumedependent and elastic energy terms with a static character have been included tocomplete the description. Such an extension enables us to construct the completethermodynamics. In particular, the model yields a practical equation of state anddescribes the thermal expansion coefficient as well as the isothermal compressibilityof solids. The thermodynamic properties resulting from the Gibbs free-energyanalysis have been calculated and are illustrated in figures. Some comparisons ofthe theoretical results with experimental data for solid argon have been made.