Spin polarization and interlayer coupling in Fe/FeAl/Fe sandwiches

Abstract Epitaxial FeAl superlattices were used as nonmagnetic spacers in MgO(0 0 1)Fe/FeAl/Fe trilayers. The magnetic hyperfine field at the nuclei of a 57 Fe probe layer, situated in the center of the FeAl spacers, being a measure of the spin polarization from the ferromagnetic Fe layers, was investigated as a function of the total spacer thickness d . A decaying oscillatory dependence of the polarization effect vs. d was found. Magnetization measurements revealed the existence of a temperature dependent 90° coupling. Finally, the correlation of the spin polarization and coupling behavior was clearly identified.