Enhanced exchange bias due to an ultra-thin, non-magnetic insulator spacer layerA. Paul, D. E. Bürgler, M. Luysberg and P. Grünberg
Institut für Festkörperforschung - Forschungszentrum Jülich GmbH D-52425 Jülich, Germany
received 11 December 2003; accepted in final form 27 August 2004
The exchange bias effect of bilayers is found to significantly increase when an ultra-thin, non-magnetic insulating x spacer is added at the ferromagnet/antiferromagnet interface. The dependence on the spacer thickness is non-monotonic with a maximum two-fold enhancement of the exchange bias field at a spacer thickness of 1.0 . These observations are explained in terms of a discontinuous layer structure of the spacer and its thickness evolution. There is no indication of a magnetic interaction across the x spacer layer.
68.65.Ac - Multilayers.
75.30.Gw - Magnetic anisotropy.
75.70.Cn - Magnetic properties of interfaces (multilayers, superlattices, heterostructures).
© EDP Sciences 2004