Microwave-Assisted Magnetization Reversal of Exchange-Coupled Composite Nanopillar With Large Gilbert Damping Constant

Microwave-assisted magnetization reversal (MAMR) characteristics of a single-exchange-coupled composite nanopillar, which consists of ferromagnetically coupled soft and hard magnetic sections, have been discussed in terms of Gilbert damping constant using micromagnetic simulation. The results indicate the occurrence of significant MAMR even when the damping constant of the hard magnetic section is large. The results obtained in this paper greatly contrast those obtained with single-phase hard magnetic pillars. We also found that the magnetization switching time tends to be shorter when the damping constant of the hard magnetic section is large.