Micromagnetic simulations with periodic boundary conditions: Hard-soft nanocomposites

TL;DR

This paper introduces a micromagnetic simulation method with periodic boundary conditions using Ewald summation, applied to study hysteresis in hard-soft nanocomposites, revealing sensitivity to interlayer exchange and optimizing soft phase size.

Contribution

A novel micromagnetic simulation approach incorporating periodic boundary conditions and Ewald summation for dipolar interactions, applied to analyze magnetic nanocomposite hysteresis.

Findings

Hysteresis in layered structures is highly sensitive to interlayer exchange strength.

The origin of hysteresis behavior was discussed in relation to magnetic parameters.

Optimal soft phase size enhances the energy product of nanocomposites.

Abstract

We developed a micromagnetic method for modeling magnetic systems with periodic boundary conditions along an arbitrary number of dimensions. The main feature is an adaptation of the Ewald summation technique for evaluation of long-range dipolar interactions. The method was applied to investigate the hysteresis process in hard-soft magnetic nanocomposites with various geometries. The dependence of the results on different micromagnetic parameters was studied. We found that for layered structures with an out-of-plane hard phase easy axis the hysteretic properties are very sensitive to the strength of the interlayer exchange coupling, as long as the spontaneous magnetization for the hard phase is significantly smaller than for the soft phase. The origin of this behavior was discussed. Additionally, we investigated the soft phase size optimizing the energy product of hard-soft nanocomposites.