Thermodynamic functions and structure of gallium + tellurium liquid alloys

In the frame of our systematic investigation on strongly interacting alloy systems, we have measured the molar enthalpy of formation, ΔH_f, of liquid Ga + Te alloy at 1200 and 1238 K by direct reaction calorimetry, using a Calvet microcalorimeter. The enthalpy of formation, with reference to the pure liquid components, is negative over the whole range of mole fractions x and has a minimum at x_Te ≈ 0.6. ΔH_f(l, x_Te = 0.61, 1200 K) = ?(38.8 ± 0.8) kJ mol^?1. This is evidence for strong chemical interactions in the liquid phase with formation of Ga₂Te₃ clusters. No significant difference was noted between the enthalpies at 1200 and 1238 K. Comparison of the molar integral enthalpies and entropies of formation of liquid Me_0.4^IIITe_0.6 alloys (Me^III  Al, Ga, In, and Tl) shows that the stability of the Me₂Te₃ clusters decreases in the series Al > Ga > In > Tl.