Spin accumulation at ferromagnet/nonmagnetic material interfaces

Abstract

Many proposed and realized spintronic devices involve spin injection and accumulation at an interface between a ferromagnet and a nonmagnetic material. We examine the electric field, voltage profile, charge distribution, spin fluxes, and spin accumulation at such an interface. We include the effects of both screening and spin scattering. We also include both the spin-dependent chemical potentials ${\ensuremath{\mu}}_{\ensuremath{\uparrow},\ensuremath{\downarrow}}$ and the effective magnetic field ${\stackrel{P\vec}{H}}^{*}$ that is zero in equilibrium. For a Co/Cu interface, we find that the spin accumulation in the copper is an order of magnitude larger when both chemical potential and effective magnetic field are included. We also show that screening contributes to the spin accumulation in the ferromagnet; this contribution can be significant.