Multiphase equation of state and thermoelastic data for polycrystalline beryllium

Abstract

We describe construction of a new multiphase equation of state (EOS) for beryllium calibrated almost entirely to density functional theory calculations based on the AM05 exchange-correlation functional. The EOS is in tabular form (as SESAME 92025) and includes hcp, bcc, and liquid/plasma phases. We find hcp→bcc transitions at ∼325 GPa at zero and room temperatures, and at ∼150 GPa on the Hugoniot. Shock melting from the bcc phase proceeds at 205-230 GPa. We also present experimental results for the isentropic bulk modulus as a function of temperature, based on resonant ultrasound spectroscopy measurements.