Regensburg 2004 – wissenschaftliches Programm

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MA: Magnetismus

MA 10: Exchange Bias

MA 10.1: Vortrag

Dienstag, 9. März 2004, 10:15–10:30, H10

Exchange coupling in thin Fe-films on NiO(001) — •U. Mick, W. G. Park, V. Bocatius, H. Meinert, and E. Kisker — Institut für Angewandte Physik, Universität Düsseldorf

The domain formation and exchange coupling of thin Fe-Films on NiO(001) have been investigated by x-ray magnetic linear dichroism (XMLD) and x-ray magnetic circular dichroism (XMCD) in photoemission electron microscopy (PEEM).

In-situ cleaved NiO crystals provide atomically defined clean NiO(001)-surfaces as is shown in complementary STM-measurements. Thin Fe-films grown by MBE at room temperature on these NiO(001)-surfaces exhibit a collinear coupling of their magnetic moments to the spin structure of by the NiO(001)-substrate as is revealed in angular dependent PEEM-measurements. Fe-films grown on freshly cleaved NiO(001) can induce changes in the NiOs AF-domains, which are presumably thermodynamically unstable. Thermally relaxed NiO(001) surfaces, that have been annealed above Neel-temperature, show a rearrangement in their domain structure that is not altered by subsequent deposition of Fe anymore while the Fe-films still show collinear coupling after the onset of FM-coupling, as has been investigated for different film thicknesses of Fe from 1 ML to 15 ML.

Neither x-ray absorption spectroscopy (XAS) nor PEEM-investigations on Ni-MCD gave any evidence for significant interface reactions between the Fe-films grown at room temperature and the NiO substrate.

This work has been performed at BESSY-UE52 and was supported by the BMBF under grant No. 05KS1PFB/1