STRUCTURAL AND MAGNETIC PROFILES IN FE/SI MULTILAYERS

Iron-silicon multilayers were prepared by vacuum evaporation and characterized by cross-sectional electron microscopy, electron diffraction, in situ electrical measurements and low-angle X-ray scattering. Mossbauer spectroscopy measurements carried out on samples with different silicon and iron thicknesses showed a distribution of the magnetic moments of the iron atoms. The Mossbauer spectra are analysed with reference to those of Fe-Si amorphous and crystalline alloys. They show iron atoms in a pure bcc crystalline phase, in a bcc crystalline phase with a silicon atom as a first neighbour, in an amorphous magnetic phase with a large hyperfine field distribution and in an amorphous non-magnetic phase. A Jaccarino-Walker type hypothesis allows us to propose a model for structural and magnetic profile of the layers which is consistent with neutron scattering and Mossbauer spectroscopy data.