Shock compression ofV2H andV2D to 135 GPa and anomalous decompression behavior

Abstract

Shock-compression measurements of ${\mathrm{V}}_{2}$H and ${\mathrm{V}}_{2}$D were performed at up to 135 GPa using a 25-mm propellant gun and a 20-mm two-stage light-gas gun. The shock velocity $U$ and particle velocity $u$ obtained by the impedance match solution can be represented by a linear relation, $U=5.51+1.10u$. The compression curve determined is found to lie close to that of vanadium metal without any indication of anomaly, showing that V---H bonds are as incompressible as V---V bonds even in this pressure range. Anomalous free-surface behavior detected as a two-step extinction of the inclined mirror trace above about 110 GPa suggests decomposition in the decompression process.