Intrinsic magnetotransport and orientation dependent topological Hall effect in EuAuBi

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.