The magnetic structure of coupled Fe/FeO multilayers revealed by nuclear resonant and neutron scattering methods

We have studied the magnetic structure that forms in a Fe/native Fe oxide multilayer by nuclear resonant scattering of synchrotron radiation and polarized neutron reflectometry. Magnetic field-dependent experiments revealed a non-collinear magnetic arrangement of the adjacent metallic layers which is mediated by an antiferromagnetically ordered oxide layer. Despite its antiferromagnetic (AFM) order, the oxide exhibits a small net magnetization attributed to the presence of metallic Fe within the AFM matrix that aligns parallel to the external field. The presence of a strong uniaxial anisotropy prevents the system from forming small magnetic domains in remanence. The canting angle between the two magnetic sublattices remains close to 90 degrees throughout the magnetization reversal on the hard axis. The results and the influence of the uniaxial anisotropy are discussed in the framework of the proximity magnetism model.