Low-Field Giant Magnetoresistance in [Ni-Fe-Co/Cu/Co/Cu] Superlattices

Abstract
[Ni-Fe-Co/Cu/Co/Cu] superlattices were prepared by RF sputtering. The superlattices showed low-field (<500 Oe) giant magnetoresistance (Δρ/ρ=15%) at RT when the Cu layer thickness was about 2 nm. The MR (magnetoresistance) ratio was found to oscillate with the Cu spacer layer thickness with a period of 1.1 nm, which implies RKKY (Ruderman-Kittel-Kasuya-Yosida)-like interlayer exchange coupling between the magnetic layers.