The thermodynamic functions of hydrogen in solid solutions of the group V metals Nb, Ta and V

Abstract

The large volume of available data for the isotherms characterizing the dissolution of H from H 2-gas into the Group V metals Nb, Ta and V has been reviewed. Both the temperature and composition variation of the partial molar and relative partial molar enthalpies and entropies have been discussed in terms of theoretical models in which the H-atoms in solution can possess degrees of translational freedom. The relative invariance of the relative partial enthalpy Δ H u to temperature and the change in H u with temperature are in accord with this concept. The variation of H u with solute composition has been used in conjunction with recent elastic data for HNb, HTa and HV solid solutions to discuss the form of the HH interaction in these systems.