Band-structure calculations of Fe_1/3TaS₂ and Mn_1/3TaS₂, and transport and magnetic properties of Fe_0.28TaS₂

Band-structure calculations of ferromagnetic Fe_1/3TaS₂ and Mn_1/3TaS₂ using the augmented spherical-wave method are reported. The calculations give a spin magnetic moment of 4.35 mu _B per Fe for Fe_1/3TaS₂ and 4.18 mu _B per Mn for Mn_1/3TaS₂. The local moments at Fe and Mn induce a magnetic polarisation of the Ta 5d(z²) band, which is parallel to the local moment for Fe_1/3TaS₂ and antiparallel for Mn_1/3TaS₂. Measurements of the transport properties of Fe_0.28TaS₂ show a large spin-disorder contribution to the resistivity and a large anomalous Hall effect. The anomalous Hall effect is analysed in terms of side jump and skew scattering contributions. The large magnetisation anisotropy indicates the presence of Fe²⁺, in agreement with the band-structure calculations.