Thermodynamic modeling of the Sb-Te system supported by DSC measurement and ab initio calculations

Nowadays, thermoelectric materials became important sources of renewable energy. Among various materials that show this property, the Sb2Te3 attracts attention due to its excellent properties. Recent experimental information revealed a new phase equilibrium data; therefore, it is reasonable to elaborate a state-of-art thermodynamic model of the binary Sb-Te system. In this work, a new thermodynamic description is proposed based on the available experimental data. In addition, a new DSC measurement of heat and temperature of fusion of Sb2Te3 as well as ab initio calculation of Sb2Te3 were included in the experimental dataset. The homogeneity range of Sb2Te3 was modeled according to the stability of defects obtained from first-principle calculations. The morphology of the optimized phase diagram follows the latest findings, which means that the Ksi phase has replaced the delta and gamma phases. The elaborated thermodynamic parameters allow for a good reproduction of experimental data as well as for future modeling of higher-ordered systems.