Tailoring the exchange bias effect by in-plane magnetic anisotropy

TL;DR

This study demonstrates how the in-plane magnetic anisotropy and spin-reorientation in ferromagnet/antiferromagnet bilayers can be manipulated to control the exchange bias effect, offering a new method for customizing magnetic properties.

Contribution

It reveals the influence of ferromagnetic layer thickness and anisotropy evolution on exchange bias in epitaxial CoO/Fe(110) bilayers, introducing a novel approach to tailor magnetic interactions.

Findings

Exchange bias exhibits a non-monotonous dependence on ferromagnetic layer thickness.

Magnetic anisotropy evolution controls interfacial spin directions and exchange bias magnitude.

Spin-reorientation process can be utilized to tailor magnetic properties in bilayer systems.

Abstract

We report an unusual, non-monotonous dependence of the exchange bias on the thickness of the ferromagnetic layer in a ferromagnet/antiferromagnet bilayer system. We show that in epitaxial CoO/Fe(110) bilayers, the evolution of the Fe magnetic anisotropy, which drives the thickness-induced in-plane spin-reorientation process, controls the interfacial CoO spin directions in the 0-90 degrees range and, consequently, drastically modifies the magnitude of the hysteresis loop shift and its dependence on the thickness of the Fe layer. Our results present a new recipe for tailoring the exchange bias and antiferromagnetic spin structure by utilizing the spin-reorientation process that occurs in a ferromagnetic layer adjacent to an antiferromagnetic layer.