A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic disks: distorted viscous vortex

Abstract

Magnetic vortices have generated intense interest in recent years due to their unique reversal mecha-nisms, fascinating topological properties, and exciting potential applications. In addition, the exchangecoupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novelphenomena and functionalities. Here we report a new magnetization reversal mode of magnetic vorticesin exchange coupled Ir20Mn80/Fe20Ni80microdots: distorted viscous vortex reversal. In contrast to thepreviously known or proposed reversal modes, the vortex is distorted close to the interface and viscouslydragged due to the uncompensated spins of a thin antiferromagnet, which leads to unexpected asymme-tries in the annihilation and nucleationfields. These results provide a deeper understanding of the physicsof exchange coupled vortices and may also have important implications for applications involvingexchange coupled nanostructures