Experiments on Microwave-Assisted Magnetization Reversal in a Submicron-Scale Permalloy Single Element with a Zero-Field Resonance Frequency of 6.3 GHz

Microwave-assisted magnetization reversal (MAMR) in a submicron-scale NiFe single element with a coercive field of 200 Oe and a zero-field resonance frequency of 6.3 GHz was investigated experimentally. Efficient reduction of the switching field due to MAMR was realized at frequencies ranging from 5.9 to 6.1 GHz. At the optimal frequency, the cusp profile characteristic of MAMR was observed in the switching yield map. By using an ac magnetic field with an amplitude of 110 Oe, the switching field can be reduced to one-fourth of the coercive field. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/APEX.2.033002