Magnetic vortex core dynamics in cylindrical ferromagnetic dots.
We report direct imaging by means of x-ray photoemission electron microscopy of the dynamics of magnetic vortices confined in micron-sized circular permalloy dots that are 30 nm thick. The vortex core positions oscillate on a 10 ns time scale in a self-induced magnetostatic potential well after the in-plane magnetic field is turned off. The measured oscillation frequencies as a function of the aspect ratio of the dots are in agreement with theoretical calculations presented for the same geometry.
Guslienko
K Yu
KY
Materials Science Division and Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA. gusliyenko@anl.gov
Han
X F
XF
Keavney
D J
DJ
Divan
R
R
Bader
S D
SD