Macrospin limit and configurational anisotropy in nanoscale Permalloy triangles

TL;DR

This paper investigates the magnetic anisotropy in nanoscale Permalloy triangles, demonstrating how shape and size influence magnetic reversal behavior through experimental and simulation methods.

Contribution

It introduces an experimental approach to quantify six-fold anisotropy fields in nanoscale triangles, linking geometry to magnetic behavior.

Findings

Identified size and thickness regimes where Stoner-Wohlfarth model applies

Quantified six-fold anisotropy fields experimentally

Validated micromagnetic simulations with experimental data

Abstract

In Permalloy submicron triangles, configurational anisotropy - a higher-order form of shape anisotropy - yields three equivalent easy axes, imposed by the structures' symmetry order. Supported by micromagnetic simulations, an experimental method was devised to evaluate the nanostructure dimensions for which a Stoner-Wohlfarth type of reversal could be used to describe this particular magnetic anisotropy. In this regime, a straightforward procedure using an in-plane rotating field allowed us to quantify experimentally the six-fold anisotropy fields for triangles of different thicknesses and sizes.