Thermodynamic properties of liquid tin-tellurium alloys at high temperature

Electromotive force measurements on galvanic cells have been performed in order to obtain the tin activity in liquid tin-tellurium alloys in the composition range 0.200 <x _Te < 0.750 and between 673 and 1123 K. The position of some liquidus points, determined by emf measurements, was verified by differential thermal analysis. Moreover calorimetric measurements were made at 873 K. By graphical integration of the Gibbs-Duhem relationship, partial molar Gibbs energy and enthalpy changes, ΔG _Te and ΔH _Te were obtained. The integral thermodynamic properties ΔH _M,TΔS _M and ΔG _M were also calculated at 1100 K. From these thermodynamic values and the variations of viscosity and electrical resistivity given in the literature and according to the essentially covalent nature of the bonding in the solid SnTe, we have qualitatively investigated the dependence of the nature and the evolution of the interactions with the temperature in the neighborhood of the compositionx _Te = 0.500. J. Rakotomavo, who is preparing his thesis