Effective uniaxial anisotropy in easy-plane materials through nanostructuring

TL;DR

This paper explores how nanostructuring easy-plane magnetic materials can induce effective uniaxial anisotropy, potentially leading to new hard-magnetic materials with increased coercivity.

Contribution

It demonstrates that exchange coupling in nanostructured easy-plane materials can produce uniaxial anisotropy, offering an alternative approach to develop permanent magnets.

Findings

Coercivity increases as feature size decreases.

The coercive field reaches about 12% of the anisotropy field at specific sizes.

Nanostructuring effectively induces uniaxial anisotropy in easy-plane materials.

Abstract

Permanent magnet materials require a high uniaxial magneto-crystalline anisotropy. Exchange coupling between small crystallites with easy-plane anisotropy induces an effective uniaxial anisotropy if arranged accordingly. Nanostructuring of materials with easy-plane anisotropy is an alternative way to create hard-magnetic materials. The coercivity increases with decreasing feature size. The resulting coercive field is about 12 percent of the anisotropy field for a crystal size of 3.4 times the Bloch parameter.