The excess enthalpies of liquid Ag-Ge-Te and Ag-Sn-Te alloys

The excess enthalpies of Liquid alloys in the ternary systems Ag-Ge-Te and Ag-Sn-Te have been determined in a heat flow calorimeter for three sections AgyGe1-y-Te with y = 0.2, 0.5, and 0.8 at 1213 K and for the section Ag0.5 Sn0.5-Te at 973, 1073, and 1173 K to complete recent measurements. The exce ss enthalpies of both systems are exothermic and decrease with increasing t emperature by the dissociation of telluride associates. The enthalpy surfac e of both systems is determined by a valley of minima from Ag2Te to GeTe an d SnTe, respectively. Preceding the analyses of the ternary excess enthalpi es the thermodynamic functions of the systems Ag-Ge and Ag-Sn were reoptimi zed with the Lukas program using the association model of Sommer for the de scription of the melt. Ternary interactions were taken into account for the analyses of the excess enthalpies of the liquid Ag-Ge-Te and Ag-SnTe alloy s.