Interfacial spin structure in epitaxial Fe/FeSn ₂ bilayers with exchange bias

Fe/FeSn2 structures with epitaxial FeSn2 layers have been grown by MBE (Molecular Beam Epitaxy). Exchange bias and pinning phenomena were proved by SQUID magnetometry. In order to elucidate the spin structure at the Fe/FeSn2 interface and in some depth of the FeSn2 layer with CEMS (Conversion Electron Mössbauer Spectroscopy), 57FeSn2 tracer layers of approx. 50 Å thickness have been incorpo- rated in the base structure, the only difference being the isotopic enrichment with 57Fe. An ellipsoidal model was applied to represent the spin structure. A strong out-of-plane component of the spin structure at the interface was observed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)