The influence of magnetic impurities in the vortex core dynamics in magnetic nano-disks

In this work we have used spin dynamics simulations to study the gyrotropic frequency behavior in nano-disks of Permalloy with magnetic impurities. We consider the effect of attractive impurity and repulsive impurity placed near the vortex core gyrotropic trajectory. We observed that the gyrotropic frequency is affected by the presence of impurity. The gyrotropic frequency shift depends on the relative position between the impurity and the vortex core gyrotropic trajectory and if impurity is attractive or repulsive. Our results agree with the analytical model and with experimental behavior for the gyrotropic frequency shown in the literature.