Intrinsic magnetotransport and orientation dependent topological Hall effect in EuAuBi

TL;DR

This study reports the growth of high-quality EuAuBi crystals using Pb flux, revealing orientation-dependent topological Hall effects linked to magnetic transitions and emphasizing the importance of crystal orientation in topological transport.

Contribution

The paper demonstrates a new crystal growth method that enables the exploration of intrinsic properties and orientation-dependent topological Hall effects in EuAuBi.

Findings

Residual topological Hall signal appears below antiferromagnetic transition.

Hall signal correlates with metamagnetic transitions and magnetoresistance anomalies.

Crystal orientation significantly affects topological transport signatures.

Abstract

We report the growth of high-quality single crystals of the magnetic topological semimetal EuAuBi using a Pb flux method, which effectively suppresses the formation of secondary Au2Bi impurity phases that were prevalent in the previously reported Bi flux grown crystals. This growth optimization enables reliable investigation of the intrinsic physical properties of EuAuBi. Importantly, Pb flux growth stablilizes c axis oriented single crystals, enabling Hall measurements in a previously unexplored geometry. In this configuration (I parallel to c, B perpendicular to c), a finite residual Hall contribution, known as topological Hall signal emerges below the antiferromagnetic ordering temperature and within a narrow magnetic field range. This Hall contribution coincides with the metamagnetic transitions, anomalies in magnetoresistance, and an additional feature in field-dependent specific heat, indicating strong coupling between the electronic transport and field induced magnetic reconstructions. Consequently, these findings underscore the significance of crystal orientation in uncovering topological transport signatures in magnetic semimetals such as EuAuBi.