Anomalous Hall Effect in Fe/Gd Bilayers

TL;DR

This study investigates the anomalous Hall effect in Fe/Gd bilayers, revealing complex temperature-dependent behavior including sign changes, explained by contrasting properties of Fe and Gd layers.

Contribution

It provides a detailed experimental analysis of the anomalous Hall effect in Fe/Gd bilayers, highlighting the role of opposite spin polarizations and differing Curie temperatures.

Findings

Non-monotonic Hall resistivity dependence on temperature

Sign change in Hall resistivity observed in Fe/Gd bilayers

Opposite signs of Hall resistivity linked to Fe and Gd layers

Abstract

Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films.