Spin-orbit strength driven crossover between intrinsic and extrinsic mechanisms of the anomalous Hall effect in epitaxial L1o FePd and FePt

TL;DR

This study investigates how spin-orbit strength influences the dominant mechanisms behind the anomalous Hall effect in epitaxial FePd and FePt alloys, revealing a crossover from extrinsic to intrinsic contributions.

Contribution

It demonstrates the spin-orbit strength driven crossover between extrinsic and intrinsic AHE mechanisms in FePd and FePt alloys, providing a way to tune AHE origins in complex materials.

Findings

FePd exhibits mainly extrinsic side-jump AHE

FePt shows dominant intrinsic AHE

Spin-orbit strength difference causes the crossover

Abstract

We determine the composition of intrinsic as well as extrinsic contributions to the anomalous Hall effect (AHE) in the isoelectronic L1o FePd and FePt alloys. We show that the AHE signal in our 30 nm thick epitaxially deposited films of FePd is mainly due to extrinsic side-jump, while in the epitaxial FePt films of the same thickness and degree of order the intrinsic contribution is dominating over the extrinsic mechanisms of the AHE. We relate this crossover to the difference in spin-orbit strength of Pt and Pd atoms and suggest that this phenomenon can be used for tuning the origins of the AHE in complex alloys.