Calculation of coercivity of magnetic nanostructures at finite temperatures

Abstract

We report a finite temperature micromagnetic method (FTM) that allows for the calculation of the coercive field of arbitrarily shaped magnetic nanostructures at time scales of nanoseconds to years. Instead of directly solving the Landau-Lifshitz-Gilbert equation, the coercive field is obtained without any free parameters by solving a nonlinear equation, which arises from the transition state theory. The method is applicable to magnetic structures where coercivity is determined by one thermally activated reversal or nucleation process. The method shows excellent agreement with experimentally obtained coercive fields of magnetic nanostructures and provides a deeper understanding of the mechanism of coercivity.