Regensburg 2007 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 19: Spin-Dynamics/Switching I

MA 19.2: Vortrag

Mittwoch, 28. März 2007, 15:30–15:45, H23

Spin waves in semi-circular Ni₈₁Fe₁₉ ring segments in the presence of domain walls — •Britta Leven, Christian Sandweg, Helmut Schultheiß, Sebastian Hermsdörfer, and Burkard Hillebrands — FB Physik and Forschungsschwerpunkt MINAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany

We present a study of spin wave properties in semi-circular Ni₈₁Fe₁₉ ring segments in the presence of domain walls. The spin wave spectra are detected with a lateral resolution of 300 nm employing micro-focus Brillouin light scattering spectroscopy. The elements are prepared using a combination of electron beam lithography and molecular beam epitaxy. The ring segments have a radius of 10 µm, a width of 500 nm and a thickness of 10 nm. In order to localize a domain wall a 200 nm wide protrusion has been added at the pole region of the ring structure, which acts as nucleation site if an external magnetic field is applied in radial direction. It is thus possible to study spin wave spectra in the element either in the presence or in the absence of a domain wall by applying an external magnetic field in radial or tangential direction, respectively. In the absence of a domain wall we observe typical spin wave quantization effects due to the confinement of the ring segment in radial direction. In contrast, in the presence of a domain wall the quantized wave profile is distorted in the vicinity of the domain wall due to the variation of the internal magnetic field. Technical support of P.A. Beck, of the Nano+Bio Center, TU Kaiserslautern and financial support by the DFG within the SPP1133 and the NEDO project No 2004IT093 funded by the Japanese government is acknowledged.