Thermodynamic properties of Ga-Zn system. Experiment vs model

Abstract

This paper contains the results of the integral molar mixing enthalpy of Ga-Zn liquid alloys, measured calorimetrically at two temperatures: 722K over the entire concentration range and 923K for the concentration range of Zn lower than 0.5at.%. Experimental values obtained in this range of temperatures indicate that the integral molar enthalpy of liquid alloys of this binary system is temperature independent. The available experimental values of the partial or molar Gibbs energies, together with the enthalpy of mixing, were used for the elaboration of the equation in the form proposed by Redlich and Kister, which describes the dependence of the excess Gibbs energy on the concentration and temperature. The experimental thermodynamic values of the excess Gibbs energy, mixing enthalpy change and activity were compared with those calculated with the use of the elaborated Redlich-Kister equation. Moreover, the partial structure factors and short-range order parameter were calculated and discussed in relation to the thermodynamic properties and the phase diagram of the Ga-Zn system.