Thermodynamic properties of liquid copper-antimony-tin alloys determined from e.m.f. measurements

The thermodynamics properties of liquid Cu-Sn-Sb alloys were determined using solid-oxide galvanic cells with zirconia electrolyte: Re + kanthal, Cu-x-Sb-y-Sn(1-x-y), SnO2//ZrO2 + (Y2O3)// NiO, Ni, Pt (I) in the temperature range from 998 to 1 223 K. The Gibbs free energy of formation of pure solid SnO2 from pure elements was derived. Using electromotive force values measured for the cell with x(Sn) = 1.0, the following temperature dependence was obtained: Delta G(f,SnO2)(0) = -567903 + 200.33T(+/- 1000 J) [J mol(-1)] Activities of tin were determined along three sections of the ternary system specified by the ratio of mole fractions x(Cu)/x(Sb) = 1:3, 1:1, and 3:1. Thermodynamic properties of the liquid phase were described by the Redlich-Kister-Muggianu formula. Using commercial software, phase relations in the ternary system were calculated. The results of the calculations are compared with experimental data available from literature.