Vortex dynamics in patterned ferromagnetic ellipses
2006; American Institute of Physics; Volume: 99; Issue: 8 Linguagem: Inglês
10.1063/1.2175602
ISSN1520-8850
AutoresKristen Buchanan, P. E. Roy, F. Y. Fradin, K. Y. Guslienko, M. Grimsditch, S. D. Bader, V. Novosad,
Tópico(s)Characterization and Applications of Magnetic Nanoparticles
ResumoThe dynamics of individual magnetic vortices and vortex pairs confined in lithographically defined ferromagnetic ellipses were measured using a microwave reflection technique. Resonance frequencies were detected in the subgigahertz range for Ni80Fe20 (Permalloy) ellipses ranging in size from 3 by 1.5μm to 1 by 0.5μm, 40nm in thickness. Micromagnetic simulations indicate that the single mode observed for one vortex is a translational mode and that the two eigenmodes associated with a vortex pair correspond to coupled translational modes of vortices with parallel or antiparallel core polarizations. The single-vortex resonance scales inversely with the ellipse size, in agreement with the simulations and analytical theory.
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