Ab initio investigation of half-metal state in zinc-blende MnSn and MnC

The electronic structure and ferromagnetism of zinc-blende (ZB) structured MnSn and MnC are investigated by the first-principles calculations within the plane-wave pseudopotential method (PWPP). We predict ZB MnSn to be a true half-metallic ferromagnet with a magnetic moment of 3.0μB per formula unit (f.u.) at the equilibrium lattice constant. We also find ZB MnC exhibits half-metallic ferromagnetism by a 5% compression with respect to the equilibrium lattice constant with a moment of 1.0μB per f.u.. The origin and nature of gap for the two compounds are analyzed according to the calculated band structures and densities of state (DOS).