Localized f-electron magnetism in the semimetal Ce3Bi4Au3

• Main Authors: Ajeesh, M. O, Kushwaha, S. K, Thomas, S. M, Thompson, J. D, Chan, M. K, Harrison, N, Tomczak, J. M, Rosa, P. F. S
• Format: Journal Article
• Language: English
• Published: 05-09-2023
• Subjects: Physics - Materials Science; Physics - Strongly Correlated Electrons
• DOI: 10.48550/arxiv.2309.02559

Ce$_{3}$Bi$_{4}$Au$_{3}$ crystallizes in the same non-centrosymmetric cubic
structure as the prototypical Kondo insulator Ce$_{3}$Bi$_{4}$Pt$_{3}$. Here we
report the physical properties of Ce$_{3}$Bi$_{4}$Au$_{3}$ single crystals
using magnetization, thermodynamic, and electrical-transport measurements.
Magnetic-susceptibility and heat-capacity data reveal antiferromagnetic (AFM)
order below $T_N=3.2$ K. The magnetic entropy $S_{\rm mag}$ reaches $R$ln2
slightly above $T_N$, which suggests localized $4f$-moments in a doublet ground
state. Multiple field-induced magnetic transitions are observed at temperatures
below $T_N$, which indicate a complex spin structure with competing
interactions. Ce$_{3}$Bi$_{4}$Au$_{3}$ shows semimetallic behavior in
electrical resistivity measurements in contrast to the majority of reported
Cerium-based 343 compounds. Electrical-resistivity measurements under
hydrostatic pressure reveal a slight enhancement of $T_N$ under pressures up to
2.3 GPa, which supports a scenario wherein Ce$_{3}$Bi$_{4}$Au$_{3}$ belongs to
the far left of the Doniach phase diagram dominated by
Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. Using realistic many-body
simulations, we confirm the semi-metallic electronic structure of
Ce$_{3}$Bi$_{4}$Au$_{3}$ and quantitatively reproduce its local moment behavior
in the paramagnetic state.