Microwave-assisted switching in granular media with continuous magnetic layers for interaction control

Abstract Optimizing switching behavior under a microwave field is a key issue for microwave-assisted magnetic recording. We study the effect of inter-grain exchange coupling by a continuous magnetic layer on microwave-assisted switching of CoCrPt-SiO2 granular media. The microwave assistance effect is improved in the low frequency region by introducing the inter-grain exchange coupling, accompanied with the reduction of the critical frequency. The maximum assistance effect is almost independent of the film structure since the two effect cancels each other. Micromagnetic simulations also show similar results on exchange coupling between grains. These results indicate that the inter-grain exchange coupling can be used to optimize the critical frequency of the media in practical application.