Thermodynamics of Formation and Evaporation of Aluminum and Aluminum Telluride Melts

Abstract

- Based on the values of aluminum telluride vapor pressure determined by the boiling point method and aluminum found by integration, the partial and integral thermodynamic functions of formation and evaporation of the aluminum-telluride system melts have been calculated. The vapor pressure of aluminum telluride ( ) above the melting point has been determined for the first time. Integral functions of alloys mixing have a maximum (entropy - 5.23±0.31 J/(mol-K), enthalpy -4.17±0.24 kJ/mol) at monotectic corresponding to 42 - 44 at. % Te in the melt. The formation of alloys is accompanied by an increase in disorder in the system and goes with heat absorption. Integral functions of evaporation monotonically decrease from aluminum to telluride, and the entropy of evaporation Al 2 Te 3 (60.71±3.37 J/(mol×K)) indirectly confirms the congruent nature of aluminum telluride evaporation. The state diagram is supplemented with the fields of melt and vapor co-consistency at atmospheric pressure and in a vacuum of 6.67 kPa, which testify to the possibility of distillation separation of the Al - Al 2 Te 3 system.