The first magnesium–chromium hydride synthesized by the gigapascal high-pressure technique

Abstract The occurrence of new magnesium-based ternary hydrides of chromium was investigated by using the gigapascal high-pressure thermal technique. Powders of MgH 2 and Cr in the molar relation of 3:1 were compressed at a pressure up to 8 GPa by using a multi-anvil machine, and then heated to 873 K. The resultant samples were studied with X-ray powder diffraction and thermal desorption spectroscopy. A new phase, Mg 3 CrH x , was discovered under hydrogen pressure at 6–8 GPa. The hydrogen desorption was observed at around 598 K for the samples containing this new phase.