Examination of the High Pressure Phase Diagram of Solid Aluminum

Recent investigations have provided a detailed but somewhat contradictory picture of the equilibrium phase diagram of solid aluminum at high pressures. Laser based ramp compression coupled with x-ray diffraction is in qualitative agreement with density functional theory calculations, but the transition pressures between FCC, HCP and BCC phases are higher than expected. In this work, we present a new theoretical examination of the solid phases of aluminum under pressure where the density response is treated by quantum Monte Carlo and the lattice vibrational degrees of freedom are investigated for anharmonic character. In this way we aim to shed light on whether the disagreement stems from the equation of state or possible kinetic effects.