Standard Enthalpies of Formation of Some 4d and 5d Transition Metal-Antimony Compounds by High Temperature Direct Synthesis Calorimetry

Thermoelectric materials have the potential to save energy by recycling the waste heat from many processes. These materials are under active development and consequently the understanding of the thermodynamics and phase equilibria of these systems is necessary. In this work we have performed a calorimetric investigation of some thermoelectric alloys, which do not contain toxic or extremely rare elements. The standard enthalpies of formation of some binary 4d and 5d antimony and transition metal (TM) compounds have been measured by high temperature direct synthesis calorimetry. The reported results are: YSb (-124.7 +/- 4.7); Y5Sb3 (-111.1 +/- 3.2); Zr5Sb3 (-65.4 +/- 3.2); RuSb2 (-16.8 +/- 1.5); RhSb3 (-33.8 +/- 2.1); Pd3Sb (-54.0 +/- 2.7); Hf5Sb3 (-55.4 +/- 3.0); OsSb2 (-7.4 +/- 4.0); IrSb3 (-45.5 +/- 2.5); PtSb2 (-53.2 +/- 1.8) in kJ/mol of atoms. We compare our results with some previously published measurements and with predicted values by ab initio calculations.