Magnetic properties of the heavy fermion antiferromagnet CeMg$_3$

TL;DR

This study investigates the magnetic and heavy fermion properties of CeMg$_3$, revealing antiferromagnetic order, Kondo effect influence, and a specific crystalline electric field ground state through comprehensive measurements and analysis.

Contribution

It provides detailed experimental characterization of CeMg$_3$, including magnetic, heat capacity, and CEF analysis, highlighting its heavy fermion behavior and magnetic ground state.

Findings

CeMg$_3$ orders antiferromagnetically at 2.6 K.

Heavy fermion behavior indicated by large Sommerfeld coefficient.

Kondo effect significantly influences magnetic properties.

Abstract

We have grown the single crystals of CeMg$_3$ and its non-magnetic analogue LaMg$_3$, which crystallize in the cubic crystal structure with the space group \textit{Fm\rm{\={3}}m}, and studied their magnetic properties on well oriented single crystals by measuring the magnetic susceptibility, magnetization and heat capacity. CeMg$_3$ orders antiferromagnetically with a N\'{e}el temperature $T_{\rm N}$ of 2.6 K. The specific heat capacity at low temperature exhibits an enhanced Sommerfeld coefficient of 370 mJ/K$^2$$...$ mol indicating the heavy fermion nature of CeMg$_3$. An estimation of Kondo temperature $T_{\rm K}$ was made and found that it is of similar magnitude as that of $T_{\rm N}$. The reduced value of the magnetization below the ordering temperature, together with the reduced entropy at the magnetic ordering temperature and the enhanced low temperature heat capacity indicates that Kondo effect plays a significant role in this compound. We have performed the crystalline electric field (CEF) analysis on the magnetic susceptibility and the heat capacity data and found that the ground state is a $\Gamma_7$ doublet with an overall splitting of 191 K.