Half-metallic ferromagnetic property of FeTiS2 based on first principles

Based on density function theory and by using the full-potential linearized augmented plane-wave method within a generalized gradient approximation, the electronic properties of FexTiS2 (x=1/4, 1/3, 1) have been calculated. The results show that FeTiS2 exhibits nearly half-metallic ferromagnetic character with about 100% carrier spin polarization around the EF at the equilibrium lattice constant. When we change a and c with equal ratio, the half-metallic ferromagnetic property of FeTiS2 is maintained up in the range of 99–101% and 109–112% of its equilibrium lattice parameters. The half-metallic ferromagnetic property can also be found in Fe1/4TiS2 and Fe1/3TiS2 when their lattice parameters expand to 110–111% and 108–111% of equilibrium lattice constants, respectively. The spin up and spin down bands of the Fe-3d components show large splitting in FeTiS2. The magnetic moment of FeTiS2 per formula unit is 2.0 μB, most of which comes from the Fe atom.