Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 40: Poster II: Bio- and Molecular Magnetism (1-9); Magnetic Coupling Phenomena/Exchange Bias (10-15); Magnetic Particlicles and Clusters (16-29); Micro and Nanostructured Magnetic Materials (30-51); Multiferroics (52-64); Spin Injection in Heterostructures (65-67); Spin-Dyn./Spin-Torque (68-93); Spindependent Transport (94-108)
MA 40.15: Poster
Freitag, 27. März 2009, 11:00–14:00, P1A
Highly ordered spin-states in epitaxial [Co/Cr/Fe/Cr(001)]n spin-valve type superlattices — •Frank Brüssing1, Boris Toperverg1, Maximilian Wolff1, Hartmut Zabel1, and Katharina Theis-Bröhl2 — 1Department of Physics, Ruhr-University Bochum, 44780 Bochum, Germany — 2University of Applied Sciences Bremerhaven, 27568 Bremerhaven, Germany
We have grown [Co/Cr/Fe/Cr(001)]n epitaxial superlattices on MgO (001) by molecular beam epitaxy with spin valve properties. We adjusted the film thickness of Fe and Co layers such that their magnetization magnitudes are roughly equal. For a proper spin-valve type behavior the Cr spacer thickness was chosen as to provide a week antiferromagnetic coupling in remanence. The quality of the layering and the epitaxial relationship were verified via x-ray methods. The layer resolved magnetization in the as-grown state and with an applied magnetic field was studied by olarized neutron reflectometry. Ferromagnetic and antiferromagnetic alignment between neighboring Co and Fe layers can be recognized via intensity variations of the superlattice Bragg peaks, which are different for odd and even orders. Interestingly, additional half-order peaks appear in the asgrown state indicating a new possibly spiral magnetic state. Applying a magnetic field removes this state irreversibly. We speculate that a combination of magnetic anisotropy and dipolar coupling during growth governs the spiral state. This project was supported by the DFG via SFB491.