Angular dependence of the magnetization reversal in exchange biased Fe/MnF2

TL;DR

This study investigates how the magnetization reversal process in Fe/MnF2 exchange-biased bilayers depends on the angle between the external magnetic field and the exchange bias direction, revealing domain wall dynamics and angular effects.

Contribution

It provides a detailed experimental analysis of angular dependence in magnetization reversal and introduces a simple effective field model to estimate the magnetization behavior.

Findings

Magnetization reversal occurs mainly through domain wall nucleation and propagation when fields are parallel to the bias.

At finite angles, the magnetization aligns perpendicular to the cooling direction within a limited field range.

The effective field model can predict the field range where magnetization is perpendicular to the external field.

Abstract

A detailed study of exchange-biased Fe/MnF2 bilayers using magneto-optical Kerr Effect shows that the magnetization reversal occurs almost fully through domain wall nucleation and propagation for external fields parallel to the exchange bias direction. For finite angles phi between bias and external field the magnetization is aligned perpendicular to the field cooling direction for a limited field range for decreasing fields. For external fields perpendicular to the bias direction the magnetization aligns with the field cooling direction for descending and ascending fields before fully reversing. The field range for which the magnetization is close to perpendicular to the external field can be estimated using a simple effective field model.