Regensburg 2007 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 26: Exchange Bias
MA 26.8: Vortrag
Donnerstag, 29. März 2007, 17:00–17:15, H10
Ultrathin planar domain-wall in NiO/Fe3O4(110) — •Ingo Peter Krug1, Franz Ulrich Hillebrecht1, Helen Gomonaj2, and Claus M. Schneider1 — 1Institut für Festkörperforschung IFF-9 "Elektronische Eigenschaften", Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 2Bogolyubov Institute for Theoretical Physics NAS of Ukraine, st.Metrologichna, 14-b, 03143, Kiev, Ukraine
Despite numerous experimental and theoretical studies, the details of exchange-mediated interface coupling and their consequences for technologically relevant effects like exchange bias are still not sufficiently understood. The work presented here is aimed at clarifying the magnetic proximity effect in both a ferrimagnetic (Fe3O4) and antiferromagnetic material (NiO), when brought into contact. The magnetic structure at the interface is altered by the interfacial exchange interaction, leading to an ultrathin planar domain-wall (3-4 ML) in the antiferromagnet as well as a small spin-reorientation in the ferrimagnet, as was observed by PEEM measurements using soft x-rays. The antiferromagnet couples spin-flop to the ferrimagnet, as is expected for the compensated (110) interface. These results are well described by a theoretical model based on continuum theory, also yielding an estimation of the interfacial superexchange coupling, which is in the order of 10 meV, close to the value in bulk NiO.