Thermodynamic properties of alloys of the binary Sb–Yb system

Abstract

Mixing enthalpies of melts of the binary Sb–Yb system have been determined for the first time in the ranges 0 < x _Yb < 0.155 at 960–1030 K and 0.89 < x _Yb < 1 at 1140 K. It has been found that the melts form with great exothermic effects, and the partial enthalpies of the components at infinite dilution are: $\Delta \bar H_{Sb}^\infty$ =–260, $\Delta \bar H_{Sb}^\infty$ =–205 kJ/mol. An ideal associated solution model has been selected to describe the temperature and concentration dependences of thermodynamic properties of the melts, and the parameters of the model have been optimized through self-consistent analysis of the available data on the phase diagram. The model description allows to calculate the Gibbs energies and entropies of mixing of the melts, the activities of the components and the molar fractions of the associates, and the enthalpies and entropies of formation of the solid phases.