Modelling of dynamics of vortex reversal in nanodisc of cobalt

Abstract By micromagnetic simulations, the dynamic of vortex-core-polarization reversal under the influence of an in-plane oriented magnetic field pulse has been examined for a 3 nm thick cobalt disc. The results are summarized in a diagram showing the range of both pulse strength and pulse width, which should be used in the aim to force a controlled toggle switch of the core of vortex in discs of diameter varying from 90 nm to 180 nm. Typical values of these parameters are the following: pulse width is in the range of one-tenth of nanosecond and pulse strength is in the range of hundred mT. The smaller disc diameter, the more right-side-limited range of pulse width. The obtained results are qualitatively similar to previously reported ones for a 200 nm diameter and 20 nm thick Permalloy discs (R. Hertel, S. Gliga, M. Fa¨hnle, C. M. Schneider, Physical Review Letters 98 (2007) 117201).