High-pressure phase transition in gallium phosphide: An x-ray-absorption spectroscopy study

Abstract

High-pressure behavior of GaP has been studied by x-ray-absorption spectroscopy in a diamond-anvil cell up to 36 GPa. The room-temperature equation of state of phase I has been determined. The transition from a fourfold (zinc-blende) to a sixfold (\ensuremath{\beta}-tin) coordination scheme is observed near 26 GPa. Analysis of the data obtained on a sample quickly depressurized from 36 GPa shows that the transition is not reversible and the recovered sample is mainly amorphous.