Netsu Sokutei, 31 (3), p. 100, (2004)



Thermodynamic Investigation of Zn-Te Alloys by Calorimetry

The heat contents of the ZnTe compound were measured by a drop calorimeter in the temperature range from 750 to 1600 K. The enthalpy of fusion of the ZnTe compound was determined as 51.1±0.3 kJ mol-1 at corresponding melting point of 1573±3 K. The heat content and heat capacity equations were derived by Shomate function for the solid compound. The enthalpy of formation of the ZnTe compound and the integral enthalpy of mixing for the liquid Zn-Te system were measured by direct reaction calorimetry at 800, 1173 and 1373 K using a high temperature twin calorimeter. The enthalpy of mixing of the liquid Zn-Te phase shows large negative values in the neighborhood of the compound composition. This behavior dependent anomalies is explained by a chemical short range order in liquid alloys. The obtained thermodynamic data for the Zn-Te system was used to reassess the system following CALPHAD standard. An associated solution model for the liquid phase and standard Gibbs energy functions for the three solid phases (Zn, ZnTe and Te) were used. The thermodynamic properties and phase diagram calculated from the reassessed system agree well with the experimental data.