High-pressure energy-dispersive x-ray-diffraction studies were carried out on the III-V compound gallium nitride to 70 GPa using a synchrotron x-ray source. A pressure-induced first-order phase transition from a wurtzite structure to a rocksalt structure was observed to begin at a pressure of 37 GPa.

• Received 6 January 1993

DOI:https://doi.org/10.1103/PhysRevB.47.12925