CALCULATION OF SOME THERMODYNAMIC PROPERTIES AND THE PHASE-DIAGRAM OF THE PB-TE SYSTEM

The strongly associated regular solution model has been used to calculate the phase diagram of the Pb-Te system, and most of the thermodynamic quantities of the Pb-Te liquid alloys at 1200 K, for which experimental values were available in the literature. These are the molar partial and mixing enthalpies, entropies and Gibbs free energies. The dissociation equilibrium constant and the pair interaction parameters used in the calculation were derived from experimental values for both the molar partial enthalpies at infinite dilution and the enthalpy of mixing at 50 at. % Te. The Pb-Te phase diagram has been calculated using the aforementioned parameters, and compared with the data reported in the literature. Agreement is generally quite good between calculated and experimental results, although we assume a negligible solubility range for PbTe in the solid state.