A new high-pressure phase of ZnSe with B9-type structure

High-pressure and high-temperature behavior of ZnSe was investigated by energy dispersive X-ray diffraction method up to 14 GPa and 800°C. A new high-pressure phase with B9 (HgS)-type structure is found near the B3-B1 phase boundary at room temperature, as predicted by an ab-initio calculation. The property and observed pressure region of the B9-type phase are in good agreement with the ab-initio calculation. At high-temperature condition above 300°C, only the direct transitions are observed between the B3 and B1 phases. The B3-B1 phase boundary is also determined to be P (GPa)=12.21−0.0039T (°C) for the temperature range between 300 and 800°C.