Systematic study of ballistic GMR in magnetic multilayers through the 3d, 4d, and 5d transition metals

We present an extensive numerical study of the ballistic current perpendicular to the plane (CPP) GMR. Using an original technique to calculate the spin conductance in the ballistic regime we studied A/B superlattices attached to pure crystalline semi-infinite leads, with A either Ni or Co, and B various 3d, 4d and 5d transition metals, with an FCC structure. From this analysis the Co/Ag and Co/Cu systems possess the larger GMR ratios, and this is mainly due to (i) a large off-set between the Cu (Ag) band and the minority spin sub-band of Co, and (ii) strong interband scattering at the interfaces in the minority spin sub-band.