title: Magnetic vortex core dynamics in cylindrical ferromagnetic dots.
abstract: 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.
authors.affiliation: Materials Science Division and Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA. gusliyenko@anl.gov
authors.forename: K Yu
authors.initials: KY
authors.lastname: Guslienko
authors.forename: X F
authors.initials: XF
authors.lastname: Han
authors.forename: D J
authors.initials: DJ
authors.lastname: Keavney
authors.forename: R
authors.initials: R
authors.lastname: Divan
authors.forename: S D
authors.initials: SD
authors.lastname: Bader