Phase Diagram and Thermodynamic Data for the Hydrogen/Vanadium System

Abstract

Ultra-high vacuum techniques have been used to investigate the hydrogen/vanadium system in the pressure, temperature and concentration ranges 10-7-10Torr (1 Torr= 133.32 Nm~2), 260-460 K, and H/V = 0-0.85 (concentrations are expressed in terms of hydrogen atom to metal atom ratios). The variations of the thermodynamic properties of the solid solution (a-phase) with composition have been determined, and the entropy data is compared with a model assuming random distribution of hydrogen in the metal and one site per metal atom.