Metallization of aluminum hydrideAlH3at high multiple-shock pressures

Abstract

A study of electrophysical and thermodynamic properties of alane ${\text{AlH}}_{3}$ under multishock compression has been carried out. The increase in specific electroconductivity of alane at shock compression up to pressure 100 GPa has been measured. High pressures and temperatures were obtained with an explosive device, which accelerates the stainless impactor up to 3 km/s. A strong shock wave is generated on impact with a holder containing alane. The impact shock is split into a shock wave reverberating in alane between two stiff metal anvils. This compression loads the alane sample by a multishock manner up to pressure 80--90 GPa, heats alane to the temperature of about 1500--2000 K, and lasts $1\text{ }\ensuremath{\mu}\text{s}$. The conductivity of shocked alane increases in the range up to 60--75 GPa and is about $30\text{ }{(\ensuremath{\Omega}\text{ }\text{cm})}^{\ensuremath{-}1}$. In this region the semiconductor regime is true for shocked alane. The conductivity of alane achieves approximately $500\text{ }{(\ensuremath{\Omega}\text{ }\text{cm})}^{\ensuremath{-}1}$ at 80--90 GPa. In this region, conductivity is interpreted in frames of the conception of the ``dielectric catastrophe,'' taking into consideration significant differences between the electronic states of isolated molecule ${\text{AlH}}_{3}$ and condensed alane.