AVS 45th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Friday Sessions
       Session MI-FrM

Paper MI-FrM9
Magnetism of Oxide NiO/@alpha@Fe@sub 2@O@sub 3@ Multilayers Studied by Magneto-Optical Faraday Effect

Friday, November 6, 1998, 11:00 am, Room 324/325

Session: Magnetization Dynamics and Magneto-Optics
Presenter: N. Keller, Université de Versailles - CNRS, France
Authors: N. Keller, Université de Versailles - CNRS, France
M. Guyot, Université de Versailles - CNRS, France
R. Krishnan, Université de Versailles - CNRS, France
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Magneto-optical Faraday measurements were performed on magnetic oxide NiO/@alpha@Fe@sub 2@O@sub 3@ multilayers. These samples have been prepared by pulsed laser deposition technique. The magnetic particularity of this model system is given by the antiferromagnetism of both base oxides NiO and @alpha@Fe@sub 2@O@sub 3@, which can only form the ferrimagnetic nickelferrite, NiFe@sub 2@O@sub 4@, by interdiffusion at the interfaces. The magnetism of this interlayer compound can be used as a local probe for the study of interdiffusion. Increasing the number of interfaces and hence the number of ferrimagnetic layers should lead to a regular increase of the total magnetic moment. Surprisingly, we observed a pronounced oscillation of the total magnetic moment with the number of interface layers.@footnote 1@ This oscillation can only be accounted for by assuming an antiparallel alignment of the moments of each interlayer with respect to the neighboring interlayers. The magneto-optical Faraday rotation was measured in the range from 1.5 eV to 3 eV on samples with a different number of interfaces. The ellipticity of the Faraday rotation shows a similar energy dependence when compared to Kerr spectra (rotation and ellipticity) of bulk NiFe@sub 2@O@sub 4@ taken from the literature. Especially two crystal field excitations at 2.3 eV at 2.8 eV appear in both spectra. However, normalization of the ellipticity by the number of interfaces doesn't show in the entire spectral range a unique dependence. At energies higher then ~2.1 eV a non - negligible difference can be observed in the normalized ellipticity for samples with different numbers of interface. @FootnoteText@ @footnote 1@N.Keller, M. Guyot, A. Das, M. Porte, R. Krishnan, Solid State Comm. 105 (1998) 333-337