Thermodynamics of liquid Ga-Sn-Zn alloys determined by vapor pressure method

Abstract

The application of the Knudsen method for solid and liquid zinc from 550 to 733 K and liquid Ga-Sn-Zn alloys from 605 to 846 K provided experimental data which made it possible to characterize the thermodynamic properties of the liquid and gaseous phases of the Ga-Sn-Zn system. The examined alloys were selected along four cross-sections for the molar fraction ratios xSn/xGa equal to 4/1, 3/2, 2/3, 1/4. For each of the cross-sections, the value of the molar fraction of zinc in the tested alloys was approx. 0.2, 0.4, 0.6 and 0.8. Based on the obtained experimental data, the values of the activity of zinc were calculated and then used in the optimization procedure, leading to the determination of the parameters of the equations characterizing the excess Gibbs energy of liquid Ga-Sn-Zn alloys as a function of temperature and composition. The excess Gibbs energy of the ternary Ga-Sn-Zn liquid alloys was described with the extrapolation method based on the binary systems as given by the Jacob-Fitzner-Muggianu approach.