Calculation of coercivity of magnetic nanostructures at finite temperatures

TL;DR

This paper introduces a finite temperature micromagnetic method (FTM) for calculating the coercive field of magnetic nanostructures across various time scales, aligning well with experimental data.

Contribution

The paper presents a novel, parameter-free method based on transition state theory for computing coercivity in magnetic nanostructures, applicable to diverse shapes and reversal mechanisms.

Findings

Excellent agreement with experimental coercive fields

Applicable to structures with thermally activated reversal

Provides insights into coercivity mechanisms

Abstract

We report a finite temperature micromagnetic method (FTM) that allows for the calculation of the coercive field of arbitrary 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 parameter by solving a non linear 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.