Properties of magnetic vortices at elevated temperatures

Abstract

Thermal properties of steady-state magnetic vortices in soft materials are numerically evaluated using the recently proposed Landau-Lifshitz-Bloch approach. Circular samples with permalloy-like parameters are simulated. Relevant properties of the vortex core, as its radius, the magnetization drop in its center, and the radius of this magnetization drop are extracted. The dependence of the vortex core radius on temperature agrees well with the theoretical predictions, if only temperature-dependent parameters are taken into account. A new effect is found, which we call magnetization squeezing, resulting from the thermodynamic nature of the Landau-Lifshitz-Bloch approach. Our results show, however, that this squeezing in vortices is a rather weak effect in permalloy.