First-principles research on influence of C dopants on magnetic and electric properties of rocksalt MgS

The 2×2×1 rocksalt C-doped MgS supercells are optimized and their magnetic and electric properties, including the half-metallicity, the conductivity and the supercell magnetic moments, are calculated or analysed by the first-principles researches based on the density functional theory. Results show that the concentration of C-dopants may cause important influence on the magnetic and the electric properties of rocksalt MgS. C dopants are inclined to have a scattering distribution. MgC_0.0625S_0.9375, ^aMgC_0.1250S_0.8750 and MgC_0.1875S_0.8125 have evident half-metallicity. They have wide spin energy gaps, thus high Curie temperature possibly. Their supercell magnetic moments are near to integral numbers 2.0, 4.0 and 6.0 μ_B. The main reason for spin polarization and half-metallicity of C-doped MgS is that there are sp hybridized orbitals in ligand compound ML₆ caused by covalent interaction between C-ions and Mg-ions.