Thermodynamic investigation of ternary Pt-Pd-Ge alloys by Knudsen effusion combined with mass spectrometry

摘要

The activities of the three components of Pd-Pt-Ge ternary meltswere measured by Knudsen effusion combined with mass spectrometryaccording to Belton and Fruehan's method. Four pseudo-binary lineswith constant mole fraction of platinum (Xpt=0.10,0.20,0.35 and0.50) were investigated. The excess free enthalpy of formation ofthe ternary melts at 1820 K over the whole range of compositionwas deduced. The data obtained allowed us to apply the associatedsolution model to the thermodynamic functions of the Pd-Pt-Geternary system and to elucidate the nature and the temperaturedependence of its short-range order as reported previously.