Spin Hall effect in van der Waals ferromagnet Fe$_{5}$GeTe$_{2}$

TL;DR

This study explores the spin Hall effect in the van der Waals ferromagnet Fe$_{5}$GeTe$_{2}$, revealing temperature-dependent behaviors linked to magnetic ordering and band structure, with implications for spintronic device development.

Contribution

It provides the first detailed investigation of the spin Hall effect in Fe$_{5}$GeTe$_{2}$, highlighting its temperature dependence and relation to magnetic phase transitions.

Findings

Enhanced SHE below Curie temperature

Distinct temperature dependence of SHE and AHE

Potential for vdW materials in spintronics

Abstract

We investigate the spin Hall effect (SHE) in a van der Waals (vdW) ferromagnet Fe$_{5}$GeTe$_{2}$ (FGT) with a Curie temperature $T_{\rm C}$ of 310 K utilizing the spin-torque ferromagnetic resonance method. In synchronization with the emergence of the ferromagnetic phase resulting in the anomalous Hall effect (AHE), a noticeable enhancement in the SHE was observed below $T_{\rm C}$. On the other hand, the SHE shows a different temperature dependence from the AHE: the effective spin Hall conductivity is clearly enhanced with decreasing temperature unlike the anomalous Hall conductivity, reflecting the variation of band-structure accompanied by the complicated magnetic ordering of the FGT. The results provide a deep understanding of the SHE in magnetic materials to open a new route for novel functionalities in vdW materials-based spintronic devices.