Electronic Impurity Scattering Induced Spin Accumulation in Metallic Thin Films

Abstract

In order to explore the spin accumulation, evaluating the spin galvanic and spin Hall effect, we utilize the semi-classical Boltzmann equation based on input from the relativistic Korringa-Kohn-Rostoker Green's function method, within the density functional theory. We calculate the spin accumulation including multiple contributions, especially skew-scattering (scattering-in term) and compare this to three different approximations, which include the isotropic and anisotropic relaxation time approximation. For heavy metals, with strong intrinsic spin-orbit coupling, we find that almost all the effects are captured within the anisotropic relaxation time approximation. On the other hand, in light metals the contributions from the vertex corrections (scattering-in term) are comparable to the induced effect in anisotropic relaxation time approximation. We put a particular focus on the influence of the atomic character of the substitutional impurities on the spin accumulation as well as the dependence on the impurity position. As impurities will break space inversion symmetry of the thin film, this will give rise to both symmetric and antisymmetric contributions to the spin accumulation. In general, we find the impurities at the surface generate the largest efficiency of charge-to-spin conversion in case of the spin accumulation. Comparing our results to existing experimental findings for Pt we find a good agreement.

References in corpus (8)

• Spin Transfer Torques
• Can Non-Equilibrium Spin Hall Accumulation be Induced in Ballistic Nanostructures?
• Spin-orbit torques in heavy metal/ferromagnet bilayers with varying strength of interfacial spin-orbit coupling
• Imaging mesoscopic spin Hall flow: Spatial distribution of local spin currents and spin densities in and out of multiterminal spin-orbit coupled semiconductor nanostructures
• Anisotropic spin Hall effect from first principles
• Skew scattering in dilute ferromagnetic alloys
• Spin diffusion length of Permalloy using spin absorption in lateral spin valves
• Spin accumulation from non-equilibrium first principles methods