Heavy fermion and Kondo lattice behavior in the itinerant ferromagnet CeCrGe3

Abstract

Physical properties of polycrystalline CeCrGe$_{3}$ and LaCrGe$_{3}$ have been investigated by x-ray absorption spectroscopy, magnetic susceptibility $χ(T)$, isothermal magnetization M(H), electrical resistivity $ρ(T)$, specific heat C($T$) and thermoelectric power S($T$) measurements. These compounds are found to crystallize in the hexagonal perovskite structure (space group \textit{P6$_{3}$/mmc}), as previously reported. The $ρ(T)$, $χ(T)$ and C($T$) data confirm the bulk ferromagnetic ordering of itinerant Cr moments in LaCrGe$_{3}$ and CeCrGe$_{3}$ with $T_{C}$ = 90 K and 70 K respectively. In addition a weak anomaly is also observed near 3 K in the C($T$) data of CeCrGe$_{3}$. The T dependences of $ρ$ and finite values of Sommerfeld coefficient $γ$ obtained from the specific heat measurements confirm that both the compounds are of metallic character. Further, the $T$ dependence of $ρ$ of CeCrGe$_{3}$ reflects a Kondo lattice behavior. An enhanced $γ$ of 130 mJ/mol\,K$^{2}$ together with the Kondo lattice behavior inferred from the $ρ(T)$ establish CeCrGe$_{3}$ as a moderate heavy fermion compound with a quasi-particle mass renormalization factor of $\sim$ 45.

7 pages, 7 figures. Accepted by Journal of Physics: Condensed Matter