Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 36: Magnetic Coupling Phenomena / Exchange-Bias
MA 36.1: Vortrag
Freitag, 31. März 2006, 10:45–11:00, HSZ 401
Probing electronic and magnetic properties of epitaxial Fe/CoO bilayers by X-Ray absorption spectroscopy — •R. Abrudan1,2, W. Kuch1, M. Bernien1, J. Miguel1, C. Tieg2, and J. Kirschner2 — 1Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee 14, D–14195 Berlin, Germany — 2Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D–06120 Halle, Germany
We investigated the magnetic coupling between a ferromagnet and an antiferromagnet using epitaxial single-crystalline Fe/CoO bilayers on Ag(001).
The CoO films exhibit (1x1) LEED patterns similar to the clean Ag(001) substrate. The vertical interlayer spacing of the CoO films, estimated from a kinematic analysis of LEED IV curves, is slightly expanded along the film normal. Magnetic measurements using the magneto-optical Kerr effect (MOKE) show a characteristic increase of the coercive field when the system is cooled down from room temperature.
X-ray absorption spectroscopy at BESSY was employed to probe the magnetic and electronic properties with elemental selectivity. Spectra taken from bilayers with different amounts of deposited Fe do not show any indication for the formation of Fe oxide at the Fe/CoO interface. X-ray magnetic circular dichroism (XMCD) measurements exhibit a small induced ferromagnetic signal at the Co L2,3 absorption edge. X-ray linear dichroism (XLD) spectra show a pronounced structural linear dichroism that can be attributed to the vertical expansion of the CoO layer. The angular dependence of the XLD signal was used to separate the magnetic and structural contributions.