Thermodynamic investigation of the Rh-Ge and Ir-Ge binary alloys

Abstract

The enthalpies of formation Δ f H m, of the Ir-Ge and Rh-Ge alloys were measured at 1266 K with respect to composition by direct reaction calorimetry (drop method) with the help of high temperature Calvet-type calorimeters. The values lead to the following equation valid for 0 < x Ir < 0.21 and 0 < x Rh < 0.32 ▪ The thermodynamic behaviour of the melts is characterized by strong negative deviations from ideality suggesting some chemical short-range order. It will be interesting to investigate in future work the thermodynamic properties of these two binaries in the concentrated range and their temperature dependence.