Giant anomalous Hall resistivity of the room temperature ferromagnet Fe3Sn2 - a frustrated metal with the kagome-bilayer structure

TL;DR

This study reports an exceptionally large anomalous Hall resistivity in the room temperature ferromagnet Fe3Sn2, a kagome-bilayer metal, revealing unconventional Hall effect behavior linked to its frustrated magnetic structure.

Contribution

It demonstrates the giant anomalous Hall effect in Fe3Sn2 and uncovers its unconventional scaling, highlighting novel mechanisms beyond traditional models in frustrated kagome metals.

Findings

Hall resistivity at 300 K is 3.2 μΩcm, 20 times higher than typical ferromagnets.

Anomalous Hall coefficient R_s is 6.7×10^{-9} Ωcm/G, three orders of magnitude larger than pure Fe.

R_s scales with resistivity as R_s ∝ ρ_xx^{3.3}, indicating unconventional Hall effect mechanisms.

Abstract

We have investigated magnetic and transport properties of the {\it kagom\'{e}-bilayer} ferromagnet Fe$_{3}$Sn$_{2}$. A soft ferromagnetism and a large anomalous Hall effect are observed. The saturated Hall resistivity of Fe$_{3}$Sn$_{2}$ is 3.2 $\mu\Omega$cm at 300 K, which is almost 20 times higher than that of typical itinerant-ferromagnets such as Fe and Ni. The anomalous Hall coefficient $R_{{\rm s}}$ is 6.7$\times10^{-9}$ $\Omega$cm/G at 300 K, which is three orders of magnitude larger than that of pure Fe. $R_{{\rm s}}$ obeys an unconventional scaling to the longitudinal resistivity, $\rho_{xx}$, of $R_{{\rm s}} \propto \rho_{xx}^{3.3}$. Such a relationship cannot be explained by the skew and/or side-jump mechanisms and indicates that the origin of the anomalous Hall effect in the frustrated magnet Fe$_{3}$Sn$_{2}$ is indeed extraordinary.