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

We derive a simple relational expression between the spin polarization ratio of resistivity, P, and the anisotropic magnetoresistance ratio, and that between the spin polarization ratio of the density of states at the Fermi energy, PDOS, and for nearly half-metallic ferromagnets. We find that P and PDOS increase with increasing j/j from 0 to a maximum value. In addition, we roughly estimate P and PDOS for a Co₂FeGa_0.5Ge_0.5 Heusler alloy by substituting its experimentally observed/into the respective expressions.