Berlin 2005 – wissenschaftliches Programm

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MA: Magnetismus

MA 8: Spindynamik I

MA 8.12: Vortrag

Freitag, 4. März 2005, 18:00–18:15, TU H1028

Field-pulse induced generation of spin waves at domain boundaries in permalloy microstructures observed by XMCD-PEEM — •A. Krasyuk¹, S.A. Nepijko¹, A. Oelsner¹, H.J. Elmers¹, C.M. Schneider², and G. Schönhense¹ — ¹Institut für Physik, Johannes Gutenberg - Universität, 55099 Mainz — ²Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, 52425 Jülich

Stroboscopic XMCD-PEEM imaging gives direct access to fast remagnetization processes. At gradients in the region of 1mT/500 ps we have observed the fast formation of blocking domains (incoherent magnetization rotation [1]) and a rapid coherent rotation of the domain magnetization [2] resulting in a field-induced magnetic flux traversing the microstructure. Here we report on measurements with a high time resolution in the 10 ps-range employing the low-α multibunch operational mode of BESSY II providing photon pulses of < 2ps width. Domain images with time increments of down to 10 ps revealed a rapid oscillation of the visible position of the domain boundaries. A micromagnetic simulation using the NIST code (OOMMF) gives evidence of the excitation of spin waves at the domain boundaries as a consequence of the fast displacement of the domain wall during the field pulse. The plane-wave like spin wave travels perpendicular to the wall thus giving rise to an apparent oscillation of the wall position with a frequency in the 10 GHz range. Financial support by BMBF (grants 05KS1UM1/5 and 05KS1BDA/9) and DFG (Schwerpunktprogramm SPP 1133) is gratefully acknowledged.

[1] C.M. Schneider et al., Appl. Phys. Lett. 85 (2004) 2562

[2] D. Neeb et al., J. Phys.: Condens. Matter (2004) in print