Soft X-ray Resonant Magnetic Scattering Studies on Fe/CoO Exchange Bias System

TL;DR

This study uses soft X-ray Resonant Magnetic Scattering to detect and analyze the induced ferromagnetic moments in the antiferromagnetic layer of an exchange bias bilayer, revealing complex temperature-dependent magnetic behaviors.

Contribution

It demonstrates the element-specific detection of induced ferromagnetic moments in the AF layer and characterizes their temperature dependence, advancing understanding of exchange bias mechanisms.

Findings

Induced ferromagnetic moments are present in the AF layer due to proximity effects.

The AF layer's F moments have both frozen and field-following components.

Temperature influences the behavior of these magnetic components.

Abstract

We have used soft X-ray Resonant Magnetic Scattering (XRMS) to search for the presence of an effective ferromagnetic moment belonging to the antiferromagnetic (AF) layer which is in close contact with a ferromagnetic (F) layer. Taking advantage of the element specificity of the XRMS technique, we have measured hysteresis loops of both Fe and CoO layers of a CoO(40 \AA)/Fe(150 \AA) exchange bias bilayer. From these measurements we have concluded that the proximity of the F layer induces a magnetic moment in the AF layer. The F moment of the AF layer has two components: one is frozen and does not follow the applied magnetic field and the other one follows in phase the ferromagnetic magnetization of the F layer. The temperature dependence of the F components belonging to the AF layer is shown and discussed.