Control of antiferromagnetic spin axis orientation in bilayer Fe/CuMnAs films

TL;DR

This study demonstrates control over the antiferromagnetic spin axis in bilayer Fe/CuMnAs films through exchange coupling, enabling manipulation of magnetic orientation via small magnetic fields.

Contribution

We reveal the exchange coupling mechanism between Fe and CuMnAs and show how the antiferromagnetic order can be rotated using small magnetic fields.

Findings

Collinear exchange coupling between Fe and CuMnAs.

Presence of a small uncompensated Mn magnetic moment antiparallel to Fe.

Rotatable staggered magnetization of CuMnAs layer under small magnetic fields.

Abstract

Using x-ray magnetic circular and linear dichroism techniques, we demonstrate a collinear exchange coupling between an epitaxial antiferromagnet, tetragonal CuMnAs, and an Fe surface layer. A small uncompensated Mn magnetic moment is observed which is antiparallel to the Fe magnetization. The staggered magnetization of the 5nm thick CuMnAs layer is rotatable under small magnetic fields, due to the interlayer exchange coupling. This allows us to obtain the x-ray magnetic linear dichroism spectra for different crystalline orientations of CuMnAs in the (001) plane.