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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 40.90: Poster

Freitag, 27. März 2009, 11:00–14:00, P1A

Magnetization dynamics in curved permalloy nanowires — •Sandra Motl-Ziegler, Lars Bocklage, Toru Matsuyama, Jesco Topp, Markus Bolte, and Guido Meier — Universität Hamburg, Institut für Angewandte Physik, Jungiusstr. 11, D-20355 Hamburg

Magnetization dynamics in nanostructures is an interesting field of research as magnetization patterns like domain walls and vortices form on these length scales. We investigate field-induced magnetization dynamics in curved permalloy nanowires placed on a waveguide. The dependence of spin-wave modes on an external magnetic field and on the excitation frequency is studied by a broadband ferromagnetic resonance setup [1]. After saturating a nanowire the field is reduced resulting in a domain wall in the curved part of the wire. In magnetic fields between -90 mT and 90 mT the frequency is swept from 45 MHz to 20 GHz by a network analyzer. Spectra are normalized with a reference measurement at a saturating field to improve the visibility of the spin-wave modes. For a wire of 6 µm length, 200 nm width, and 20 nm thickness with an outer radius of 3 µm we identify five modes. The measurements are compared with numerical simulations based on the Landau-Lifshitz-Gilbert equation to support the experimental results. Permalloy stripes and wires with different radii are also studied.
[1] J. Podbielski et al., Phys. Rev. Lett. 96, 167207 (2006)