Shape and surface anisotropy effects on the hysteresis of ferrimagnetic nanoparticles

TL;DR

This study uses Monte Carlo simulations to explore how surface anisotropy and particle shape influence magnetization reversal mechanisms in ferrimagnetic nanoparticles, revealing the formation of hedgehog-like structures at high surface anisotropy.

Contribution

It provides new insights into the effects of surface anisotropy and shape on the magnetic behavior of ferrimagnetic nanoparticles through detailed simulation analysis.

Findings

Hedgehog-like structures form at high surface anisotropy.

Shape influences the magnetization reversal process.

Surface anisotropy alters the reversal mechanism.

Abstract

We present the results of Monte Carlo simulations of a model of a single maghemite ferrimagnetic nanoparticle with the aim to clarify the role played by the increased anisotropy at the surface and by the shape (spherical or elliptical) of the particle on the magnetization processes at low temperatures. The formation of hedgehog-like structures for high enough surface anisotropy is responsible for a change in the reversal mechanism of the particles.