Heavy fermion and Kondo lattice behavior in the itinerant ferromagnet CeCrGe3

Physical properties of polycrystalline CeCrGe${}_3$ and LaCrGe${}_3$ have been investigated by x-ray absorption spectroscopy, magnetic susceptibility $\chi (T)$, isothermal magnetization M(H), electrical resistivity $\rho (T)$, specific heat C($T$) and thermoelectric power S($T$) measurements. These compounds are found to crystallize in the hexagonal perovskite structure (space group $\mathit{\text{P6}}{}_3\mathit{\text{/mmc}}$), as previously reported. The $\rho (T)$, $\chi (T)$ 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 $\rho$ and finite values of Sommerfeld coefficient $\gamma$ obtained from the specific heat measurements confirm that both the compounds are of metallic character. Further, the $T$ dependence of $\rho$ of CeCrGe${}_3$ reflects a Kondo lattice behavior. An enhanced $\gamma$ of 130 mJ/mol,K${}^2$ together with the Kondo lattice behavior inferred from the $\rho (T)$ establish CeCrGe${}_3$ as a moderate heavy fermion compound with a quasi-particle mass renormalization factor of $\sim$ 45.