Single-ion Kondo Scaling of the Coherent Fermi Liquid Regime in Ce1-xLaxNi2Ge2

TL;DR

This study investigates the evolution of Kondo physics in Ce1-xLaxNi2Ge2 alloys, revealing a transition from non-Fermi liquid to Fermi liquid behavior and confirming the applicability of the Kondo impurity model across regimes.

Contribution

It provides detailed thermodynamic and transport measurements demonstrating the single-ion Kondo scaling in a coherent Fermi liquid regime within a dilute Ce alloy system.

Findings

Kondo temperature decreases from 30 K to 1 K with dilution.

No new energy scale associated with coherent Kondo lattice formation.

The 4f-electron contribution follows the Kondo impurity model predictions.

Abstract

Thermodynamic and transport properties of the La-diluted Kondo lattice CeNi2Ge2 were studied in a wide temperature range. The Ce-rich alloys Ce1-xLaxNi2Ge2 were found to exhibit distinct features of the coherent heavy Fermi liquid. At intermediate compositions (0.7 <= x <= 0.9) non-Fermi liquid properties have been observed, followed by the local Fermi liquid behavior in the dilute limit. The 4f-electron contribution to the specific heat was found to follow the predictions of the Kondo impurity model both in the local as well as coherent regimes, with the characteristic Kondo temperature decreasing rapidly from about 30 K for the parent compound CeNi2Ge2 to about 1K in the most dilute samples. The specific heat does not show any evidence for the emergence of a new characteristic energy scale related to the formation of the coherent Kondo lattice.