Spin polarization ratios of resistivity and density of states estimated from anisotropic magnetoresistance ratio for nearly half-metallic ferromagnets

Abstract

We derive a simple relational expression between the spin polarization ratio of resistivity, Pρ, and the anisotropic magnetoresistance ratio Δρ/ρ, and that between the spin polarization ratio of the density of states at the Fermi energy, PDOS, and Δρ/ρ for nearly half-metallic ferromagnets. We find that Pρ and PDOS increase with increasing |Δρ/ρ| from 0 to a maximum value. In addition, we roughly estimate Pρ and PDOS for a Co2FeGa0.5Ge0.5 Heusler alloy by substituting its experimentally observed Δρ/ρ into the respective expressions.