PUB - Publikationen an der Universität Bielefeld

Magnetic and structural properties of Fe/Si, Fe/Fe33Si66 and Co/Si multilayers have been studied. Very strong AF coupling J=-1.93 mJ/m(2) accompanied by saturation field of 1.5 T has been found for d(Si) = 1.4 nm. The CEMS spectra recorded at room temperature consist of the Zeeman sextet characteristic of the pure Fe phase accompanied by two spectral components related to FeSi system: magnetic broad sextet and a quadrupole doublet. The broad sextet could originate from various Fe sites at the interface. The nonmagnetic QS doublet is most probably associated with the nonstoichiometric c-Fe1-xSix phase. Comparing the results obtained for Fe/Si and Fe/Fe33Si66 multilayers we conclude that the exchange coupling is distinctly stronger for nominally pure spacer layer. For Co/Si multilayers a very weak antiferromagnetic coupling and oscillatory F-AF(d(Si)) behaviour was observed, most probably due to the formation of Co-Si nonmagnetic metallic phases replacing the nominally pure Si spacer layers. We have shown that AF coupled Fe/Si multilayers can be successfully applied as an antiferromagnets in the magnetoresistive (Fe/Si)(15)/Fe/Col/Cu/Co2 system.