Berlin 2008 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 4: Magnetic Coupling Phenomena; Exchange Bias
MA 4.8: Vortrag
Montag, 25. Februar 2008, 12:00–12:15, H 1028
Spatially resolved magnetic reversal in a multilayered exchange bias system — •Kai Schlage1, Ralf Röhlsberger1, Torsten Klein2, Eberhard Burkel2, Cornelius Strohm3, and Rudolf Rüffer3 — 1Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany — 2Universität Rostock, Rostock, Germany — 3European Synchrotron Radiation Facility, Grenoble, France
We have observed the magnetic reversal of an exchange bias [1] model system on both sides of the FM/AFM interface via nuclear resonant scattering of synchrotron radiation from 57Fe sensor layers. This yields a clear picture because one obtains the spin direction [2] and the fraction of uncompensated moments with nm depth resolution. The reversal of the ferromagnet along the easy axis proceeds via formation of a domain structure with perpendicular domain walls that extends across the FM/AFM interface. This is responsible for archetypal exchange bias characteristics like the small magnitude of the bias and the asymmetric shape of the hysteresis loop. On the other hand, along the hard axis coherent rotation of the FM winds up a planar domain wall into the AFM which is in accordance with the Mauri model.
[1] A. E. Berkowitz et al., J. Magn. Magn. Mater. 200, 522 (1999) [2] R. Röhlsberger et al., Phys. Rev. Lett. 89, 237201 (2002)