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 40.77: Poster
Freitag, 27. März 2009, 11:00–14:00, P1A
Spatially and Time-Resolved Scanning Kerr Microscopy on Permalloy Microstructures — •Andreas Krohn, Sebastian Mansfeld, Felix H. R. Balhorn, Detlef Heitmann, and Stefan Mendach — Institut für Angewandte Physik, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg
We report on microwave induced spin waves in narrow permalloy wires with typical thicknesses and widths of 20 nm and 5 µm, respectively. We have set up a novel experiment, where the microwave frequency is synchronized with the pulses of the laser used to detect the magnetization in the sample via the magneto optical Kerr effect. This enables time and spatially resolved measurements of spin waves in the permalloy structures. Due to the geometric boundary conditions in our samples spin waves underlie quantization effects and spin-wave modes are formed. We investigate the propagation of these spin-wave modes for several resonance conditions and find frequency dependant propagation velocities in the region of 100.000 m/s. We compare our findings with an analytical model based on spin waves in ferromagnetic films combined with quantization rules and micromagnetic simulations performed by OOMMF.
We thank the Deutsche Forschungsgemeinschaft for financial support via SFB 668 and 508.