Thermodynamic Properties of Ge-Y Alloys and Binary Systems of Germanium with Transition Metals

Abstract

The partial (for yttrium) mixing enthalpies of Ge–Y melts are determined using high-temperature isoperibolic calorimetry at 1780 ± 5 over a concentration range 0 < x_Y < 0,4 . These data are used to calculate the integral mixing enthalpy of the melts. The formation of Ge–Y alloys is accompanied by substantial exothermic effects. The ΔH values for Ge-Y liquid alloys are generalized on the basis of our and literature data. The activities of the components of Ge–Y melts are calculated using the liquidus coordinates of the Ge–Y phase diagram. The values obtained are characterized by very large negative deviations from the Raoult law. The thermochemical properties of Ge–3d–Me melts, dimensional and electrochemical factors, and the occupation of the valence d-orbitals of transition metals are analyzed.