Resonant modes of vortex structures in soft-magnetic nanodiscs

We present micromagnetic finite-element simulations on the dynamic response of a soft-magnetic disc exposed to ail oscillatory field applied in the disc plane. The disc is magnetized in a vortex state. At lower frequencies (about 200 MHz in our example) we find a motion of the vortex core on an elliptical orbit as a resonant mode. At higher frequencies, the out-of-plane component of the magnetization becomes resonant by the excitation of standing magnetostatic waves. (C) 2003 Elsevier B.V. All rights reserved.