Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 26: Spin Dynamics / Spin -Torque II

MA 26.11: Vortrag

Donnerstag, 28. Februar 2008, 17:15–17:30, EB 301

Spatio-temporal magnetic imaging with a femtosecond laser Kerr microscope — •Thomas Eimüller, Jie Li, Min-Sang Lee, Wei He, and Björn Redeker — Nachwuchsgruppe Magnetische Mikroskopie, Ruhr-Universität Bochum, D-44780 Bochum

We report on first results obtained with our new femtosecond laser scanning Kerr microscope. The abilities of the instrument to study magnetization dynamics with a temporal resolution below 100 fs and a lateral resolution in the sub-micrometer regime is demonstrated in all-optical two-colour pump-probe experiments. In a wedged Fe/Gd sample we record the dynamic polar MOKE signal both as a function of the film thickness gradient and as a function the delay time. The resulting spatio-temporal images reveal how the demagnetization process and the induced spin precession change as a function of the film thickness. The high lateral resolution is furthermore used to study the the reversal and magnetization dynamics of lithographically structured Co/Pt systems as a function of different geometrical shapes and different sizes of the elements.

Financial support by the DFG via project SFB491-N1 is gratefully acknowledged.