Composition Dependence of the Magnetoresistance for Ni-Co/Cu and Co-Fe/Cu Multilayer Films

The composition dependence of the giant magnetoresistance due to the interlayer exchange coupling of Ni-Co/Cu and Co-Fe/Cu multilayer films was studied. Samples were prepared by magnetron sputtering on a glass substrate. They had an fcc (111) preferred orientation parallel to the growth direction. Both the MR ratio and the saturation field were observed to oscillate as functions of the Cu thickness in both systems studied. The peak values of the MR ratio and saturation field as functions of the magnetic layer composition exhibited maxima near the electron number of Co, in qualitative agreement with theoretical calculations based on the Anderson model.