Phase diagram and thermodynamic data for the hydrogen/ vanadium system

Ultra-high vacuum techniques have been used to investigate the hydrogen/vanadium system in the pressure, temperature and concentration ranges 10–7–10 Torr (1 Torr = 133.32 N m–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 (α-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.