Elastic Properties of Vanadium. II. The Role of Interstitial Hydrogen

A detailed study was made of anomalies in the temperature dependence of the thermal expansion and of the elastic constants of several single crystals of vanadium. The anomalies were characterized by a transition temperature $T_C$, different for each crystal and lying in the temperature range 160-270 K. A simple thermodynamic theory based on a hydride-precipitation model due to Westlake accounts for the experimental results. The applicability of this model points to the precipitation of interstitial hydrogen as the cause of the observed anomalies.