Kondo behavior and metamagnetic phase transition in a heavy fermion compound CeBi2

TL;DR

This study investigates the heavy fermion compound CeBi₂, revealing Kondo behavior, an antiferromagnetic transition at 3.3 K, a metamagnetic transition, and significant negative magnetoresistance, highlighting complex electron interactions.

Contribution

It provides a comprehensive analysis of CeBi₂'s transport and thermodynamic properties, emphasizing its potential for studying f-electron and Fermi sea interactions.

Findings

Antiferromagnetic transition at ~3.3 K

Metamagnetic transition observed in magnetization

Large negative magnetoresistance across temperature and field ranges

Abstract

Heavy fermions represent an archetypal example of strongly correlated electron systems which, due to entanglement among different interactions, often exhibit exotic and fascinating physics involving Kondo screening, magnetism and unconventional superconductivity. Here we report a comprehensive study on the transport and thermodynamic properties of a cerium-based heavy fermion compound CeBi$_2$ which undergoes an anti-ferromagnetic transition at $T_N$ $\sim$ 3.3 K. Its high temperature paramagnetic state is characterized by an enhanced heat capacity with Sommerfeld coefficient $\gamma$ over 200 mJ/molK$^2$. The magnetization in the magnetically ordered state features a metamagnetic transition. Remarkably, a large negative magnetoresistance associated with the magnetism was observed in a wide temperature and field-angle range. Collectively, CeBi$_2$ may serve as an intriguing system to study the interplay between $f$ electrons and the itinerant Fermi sea.