Diffracted magneto-optical Kerr effects of permalloy ring arrays - art. no. 10J712

摘要

Diffracted magneto-optical Kerr effect (MOKE) technique was used to study the quasistatic magnetization switching of thin-film permalloy ring structures. Two different switching mechanisms were observed, dependent on the width of the annular portion of the ring. For small widths, a two-step switching is found, from an initial onion state to a state of circulation magnetization around the ring to a final onion state. In the wider rings, the switching from the circulation state to the onion state takes place via nucleation of a vortex within the annulus. The presence of the vortex is determined by the higher spatial frequency information revealed by diffracted MOKE, and through comparison with micromagnetic simulation. (c) 2005 American Institute of Physics.