Localized f-electron magnetism in the semimetal Ce3Bi4Au3

TL;DR

This study investigates the magnetic and electronic properties of Ce3Bi4Au3, revealing localized f-electron magnetism, antiferromagnetic order, semimetallic behavior, and complex magnetic transitions, supported by experimental and theoretical analyses.

Contribution

It provides the first detailed characterization of Ce3Bi4Au3's magnetic and electronic properties, highlighting its localized f-electron magnetism and semimetallic nature, distinct from similar compounds.

Findings

Antiferromagnetic order below 3.2 K.

Semimetallic electrical resistivity behavior.

Complex field-induced magnetic transitions.

Abstract

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.