Shock compression of vanadium hydrides and deuterides with different concentrations of gas atoms

Abstract

This paper presents the results of experimental studies of the shock compression of samples of vanadium deuterides and hydrides of the following compositions: VX_0.51, VX_0.7–0.9, and VX_≥1.6, where X is H or D. The experiments were carried out in the pressure range 20–140 GPa. The technology of synthesizing samples using electrolytic vanadium of not less than 99.7% purity. The Hugoniots of vanadium deuterides and hydrides were determined using the well-known reflection method. The samples were compressed using shock-wave generators based on the use of explosive charges of different power. The obtained experimental data are described by an equation of state developed using a model in which the specific heats and Gr¨uneisen ratios of ions and electrons are functions of density and temperature. At low temperature, the specific heat changes in accordance with the Debye theory. The removal of the degeneracy of the electron gas at higher temperatures is considered. The influence of ionization processes on the thermodynamic functions is effectively taken into account.