On the theory of the spin-orbit interaction in the magnetoresistivity effects in ferromagnetic metals

Abstract

Two physically different models, which have been used to explain magnetoresistance measurements in polycrystalline ferromagnetic metals, are extended to the case of single crystal ferromagnetic metals in an attempt to explain the observed anisotropy in the magnetoresistivity. It is shown in one of these models that the s-d scattering model, as developed by Smit, is inconsistent with the Döring equations unless it is assumed that the first-order spin-orbit interaction vanishes and only the second and higher orders remain. The second model which is considered, approaches the magnetoresistance effect from the viewpoint of the anisotropy in the velocity of the d-shell electrons; it is found that the anisotropy in the resistivity arises from the second-order spin-orbit interaction.