Giant-magnetoresistance calculation for {111} Co/Cu/Co spin valves

We calculate the canting-angle and thickness dependence of the current-in-plane giant magnetoresistance (CMR) of a system. consisting of a copper slab between two cobalt slabs, where the canting angle is the angle between the magnetization vectors of the two cobalt slabs. We utilize the layer-Kohn-Korringa-Rostoker method to self-consistently calculate the electronic structure. Electron scattering by impurities, phonons, magnons, etc., is modeled with a layer- and spin-dependent complex self-energy. Scattering rates are chosen to match Cu and Co resistivities. The scattering rate for minority Co is assumed to be seven times larger than for majority Co, the same ratio as for the Fermi energy density of states in the two channels. The nonlocal layer-dependent conductivity is calculated using the Kubo-Greenwood formula. We find that the CMR decreases with copper thickness in a nonuniform manner due to changes in the behavior of waveguidelike modes in the copper slab. For fixed copper thickness the GMR dependence on cos theta, where theta is the relative angle between the cobalt slabs magnetization direct-ions, deviates from a linear dependence on cos theta. [S0163-1829(98)01138-2].