Conjugate gradient methods in micromagnetics

TL;DR

This paper compares conjugate gradient methods for energy minimization in micromagnetics, demonstrating their efficiency and reliability in computing hysteresis properties and investigating demagnetizing effects in permanent magnets.

Contribution

It introduces an effective application of conjugate gradient techniques with controlled step length for micromagnetic energy minimization, especially in hysteresis and demagnetization studies.

Findings

Conjugate gradient methods are fast and reliable for hysteresis calculations.

Demagnetizing effects reduce coercive field by 1.4 T at 450 K.

Controlled step length improves convergence in micromagnetic simulations.

Abstract

Conjugate gradient methods for energy minimization in micromagnetics are compared. When the step length in the line search is controlled, conjugate gradient techniques are a fast and reliable way to compute the hysteresis properties of permanent magnets. The method is applied to investigate demagnetizing effects in NdFe12 based permanent magnets. The reduction of the coercive field by demagnetizing effects is 1.4 T at 450 K.