Exchange bias of a ferromagnetic semiconductor by a ferromagnetic metal

TL;DR

This paper reports the observation of exchange bias in a ferromagnetic semiconductor (Ga,Mn)As induced by an antiferromagnetic coupling with a ferromagnetic Fe overlayer, with element-specific evidence of a polarized interface layer.

Contribution

It demonstrates exchange bias in (Ga,Mn)As caused by Fe, revealing an interface layer that remains polarized at room temperature, using x-ray magnetic circular dichroism.

Findings

Bias fields up to 240 Oe observed.

Element-specific measurements identify a strongly exchange coupled interface layer.

The interface layer remains polarized at room temperature.

Abstract

We demonstrate an exchange bias in (Ga,Mn)As induced by antiferromagnetic coupling to a thin overlayer of Fe. Bias fields of up to 240 Oe are observed. Using element-specific x-ray magnetic circular dichroism measurements, we distinguish a strongly exchange coupled (Ga,Mn)As interface layer in addition to the biassed bulk of the (Ga,Mn)As film. The interface layer remains polarized at room temperature.