Localized f -electron magnetism in the semimetal Ce3Bi4Au3

Ce3Bi4Au3 crystallizes in the same noncentrosymmetric cubic structure as the prototypical Kondo insulator Ce3Bi4Pt3. Here we report the physical properties of Ce3Bi4Au3 single crystals using magnetization, thermodynamic, and electrical-transport measurements. Magnetic-susceptibility and heat-capacity data reveal antiferromagnetic order below TN=3.2K. The magnetic entropy Smag reaches Rln2 slightly above TN, which suggests localized 4f moments in a doublet ground state. Multiple field-induced magnetic transitions are observed at temperatures below TN, which indicate a complex spin structure with competing interactions. Ce3Bi4Au3 shows semimetallic behavior in electrical resistivity in contrast to the majority of reported cerium-based 343 compounds which are semiconducting. Electrical-resistivity measurements under hydrostatic pressure reveal a slight enhancement of TN under pressures up to 2.3 GPa, which supports a scenario wherein Ce3Bi4Au3 belongs to the far left of the Doniach phase diagram dominated by Ruderman-Kittel-Kasuya-Yosida interactions. Using realistic many-body simulations, we confirm the semimetallic electronic structure of Ce3Bi4Au3 and quantitatively reproduce its local moment behavior in the paramagnetic state.