Optical reflectivity and amorphization of GaAs during decompression from megabar pressures

Abstract
Polycrystalline GaAs was studied in a diamond anvil cell by optical reflection spectroscopy and energy‐dispersive x‐ray diffraction to pressures of 115 GPa (1.15 Mbar). Complete amorphization was observed at ambient conditions after decompression from 115 GPa, and, subsequent compression caused crystallization around 27 GPa to an orthorhombic phase. The results are compared with other group IV and III‐V semiconductor materials and implantation‐amorphized GaAs.