HIGH-PRESSURE PHASE OF MGTE - STABLE STRUCTURE AT STP

The crystal structure of MgTe has been studied in a diamond anvil cell using energy dispersive x-ray diffraction to 60 GPa at room temperature. The first pressure-induced structural phase transformation among magnesium chalcogenides was observed for MgTe at P1-3.5 GPa. The new phase has been indexed as the NiAs structure and it persisted after unloading to low pressure (0.2 GPa) and annealing for 10 h at 100° C. This is the first experimental evidence consistent with a recent theoretical prediction that for low temperature the ground state of MgTe is the NiAs structure. It is also the first pressure-induced wurtzite to NiAs transition. © 1995 The American Physical Society.