Enthalpies of mixing in ternary Ag–Eu–Sn liquid alloys

Abstract

The enthalpies of mixing in liquid alloys of the ternary Ag–Eu–Sn system were determined over a wide range of concentrations by means of isoperibolic calorimetry in the temperature range from 1313 to 1373 K. The partial enthalpies of each component of the ternary system were measured along the following sections: Δ H ̄ Ag ${\Delta }{\bar{H}}_{\text{Ag}}$ along the section with x Eu /x Sn = 0.28/0.72 up to silver content of about x Ag = 0.2 at 1373 K; Δ H ̄ Sn ${\Delta }{\bar{H}}_{\text{Sn}}$ along three sections (x Ag/x Eu = 0.31/0.69, 0.50/0.50 and 0.70/0.30) up to x Sn = 0.35 at 1373 K; Δ H ̄ Eu ${\Delta }{\bar{H}}_{\text{Eu}}$ along the section x Ag/x Sn = 0.50/0.50 up to x Eu = 0.25 at 1313 K. The enthalpies of mixing in the liquid Ag–Eu–Sn alloys show exothermic effects, being more pronounced in the vicinity of the Eu–Sn binary constituent. The minimum value of the integral enthalpy of about −60 kJ mol−1 is observed in the composition region of the congruently melting Eu2Sn phase.