Magnetic and electric properties of the metallic kagome antiferromagnet CrRhAs

TL;DR

This study reports the synthesis and characterization of CrRhAs, a kagome antiferromagnet, revealing unique Hall effect behaviors linked to Fermi surface topology and magnetic transition, advancing understanding of electric transport in magnetic materials.

Contribution

First detailed experimental investigation of CrRhAs's magnetic and electronic properties, highlighting its Fermi surface reconstruction and Hall effect anomalies.

Findings

Antiferromagnetic transition at 150 K confirmed by transport and magnetic measurements.

Hall coefficient changes sign depending on current and magnetic field orientation.

Enhanced Hall coefficient below T_N suggests Fermi surface reconstruction or magnon scattering.

Abstract

CrRhAs is an antiferromagnetic kagome metal predicted to host a nontrivial spin texture with vector spin chirality [Huang \textit{et al.}, \textit{npj Quantum Mater.} \textbf{8}, 32 (2023)]. We report the synthesis and basic characterization of CrRhAs single crystals, which exhibit an antiferromagnetic transition with $T_{\rm N}$ = 150~K, evidenced by electrical transport, heat capacity, and magnetization measurements. Hall resistivity varies linearly with magnetic field, i.e., there is no nonlinear Hall contribution. Intriguingly, the Hall coefficient changes sign between the configurations of $j \parallel ab, H \perp ab$ and $j \parallel c, H \perp c$, which is likely connected to a peculiar topology of the Fermi surface. Furthermore, for $j \parallel ab$, the Hall coefficient shows a pronounced and continuous enhancement below $T_{\rm N}$, signaling a significant reconstruction of the Fermi surface or an extra scattering from the magnons. Our results offer guidance for exploring anomalous electric transport phenomena in exotic magnetic systems.