Anomalous Hall effect mechanisms in quasi-2D van der Waals ferromagnet Fe0.29TaS2

TL;DR

This study investigates the mechanisms behind the anomalous Hall effect in quasi-2D van der Waals ferromagnet Fe0.29TaS2, revealing a transition from extrinsic to intrinsic mechanisms as the material's thickness decreases.

Contribution

It provides the first systematic analysis of AHE mechanisms in Fe0.29TaS2 across different thicknesses, linking the change to conductivity variations.

Findings

AHE mechanism shifts from extrinsic to intrinsic with decreasing thickness.

The crossover correlates strongly with changes in channel conductivity.

Systematic measurement across thicknesses elucidates AHE behavior in 2D ferromagnets.

Abstract

The recent emergence of two-dimensional (2D) van der Waals ferromagnets has provided a new platform for exploring magnetism in the flatland and for designing 2D ferromagnet-based spintronics devices. Despite intensive studies, the anomalous Hall effect (AHE) mechanisms in 2D van der Waals ferromagnets have not been investigated yet. In this paper, we report the AHE mechanisms in quasi-2D van der Waals ferromagnet Fe0.29TaS2 via systematically measuring Fe0.29TaS2 devices with thickness from 14 nm to bulk single crystal. The AHE mechanisms are investigated via the scaling relationship between the anomalous Hall and channel conductivities. As the Fe0.29TaS2 thickness decreases, the major AHE mechanism changes from extrinsic scattering to intrinsic contribution. The crossover of the AHE mechanisms is found to be highly associated with the channel conductivities as the Fe0.29TaS2 thickness varies.