Interlayer coupling and spin polarization of the nonmagnetic layers in Fe/Cu and Fe/Ag CMFs

Compositionally modulated films (CMFs) of Fe/Cu and Fe/Ag, made by RF sputtering, were investigated with ferromagnetic resonance (FMR), nuclear magnetic resonance (NMR), and magneto-optical (MO) spectroscopy. Evidence of spin polarization of the nonmagnetic layers, related to the interlayer coupling, was obtained. Direct evidence of the penetration of an exchange field and the spin polarization of the conduction electrons in the nonmagnetic Cu layers was obtained in Fe/Cu CMFs by NMR. Spin-wave resonances were observed in Fe/Cu CMFs in FMR experiments, and the spin wave was found to be sustained by both the Fe and Cu sublayers. The MO spectra of Fe/Ag CMFs indicated that the conduction electrons of Ag are spin polarized and give an additional MO activity.