Berlin 2008 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 24: SYM Thin Film Magnetic Materials: Microstructure, Reaction and Magnetic Coupling III

MM 24.1: Invited Talk

Wednesday, February 27, 2008, 14:00–14:30, H 1058

Nanoscaled domain structures and magnetization processes in thin films — •Volker Neu, Cristina Bran, Felix Fleischhauer, Aarti Singh, Ulrike Wolff, and Ludwig Schultz — IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany

Magnetic thin films and multilayers display a fascinating variety of domain structures and magnetization processes due to competing interactions. For single layers one has to consider intra- and intergrain exchange interactions and magnetostatic interactions versus complex anisotropies. In multilayer systems, additional interlayer interactions (e.g. exchange bias, antiferromagnetic or ferromagnetic coupling) broaden the range of possible coupling scenarios and thus the diversity of the magnetic behavior.

For a microscopic understanding of the magnetization processes we perform magnetic force microscopy (MFM), which offers a direct observation of the domain structure on a length scale down to 10 nm, and its evolution in a magnetic field. We present multilayers with perpendicular anisotropy and antiferromagnetic interlayer coupling of the type [(Co/Pt)_XCo/Ru]_N, which possess complex antiferromagnetically and ferromagnetically coupled domain structures, depending on temperature and magnetic history. As an example of a highly anisotropic single layer film with in-plane easy axis orientation, the magnetization process of a nanocrystalline epitaxial SmCo₅ film is investigated. Whereas the magnetizing process proceeds on a small length scale of 100 nm, in the demagnetizing process the switching occurs via a fast propagation of few interaction domain walls.