Structural stability and half metallic features of Zn_0.5Cr_0.5S under pressure

Spin-polarized first-principle was performed to study the structural stability and the electronic states of Cr doped ZnS with the Cr component of 50% in zincblende (ZB), wurtzite (W) and rocksalt (RS) structures under pressure. The results show that the zincblende and wurtzite structures become unstable under low pressures of about 4.68 and 9.61GPa, respectively, but the rocksalt structure can be maintained up to an extremely high pressure of about 32.92GPa. Both zincblende and wurtzite Zn_0.5Cr_0.5S display half metallic features under pressure, while rocksalt Zn_0.5Cr_0.5S exhibits metallic feature. The half metallic features can be ascribed to the stronger interactions between S-3p and Cr-3d states and the metallic feature is due to the higher crystal symmetry of rocksalt Zn_0.5Cr_0.5S. These results can provide helpful guidance for Cr doped ZnS to be used in spintronic devices.