Probing the localized to itinerant behavior of the 4f electron in CeIn3-xSnx by Gd3+ electron spin resonance

TL;DR

This study uses Gd3+ ESR to investigate how the Ce 4f electron in CeIn3-xSnx transitions from localized to itinerant behavior as Sn content varies, especially near the quantum critical point.

Contribution

It demonstrates the change in Ce 4f electron character with Sn substitution using ESR, revealing coexistence of localized and itinerant behaviors near criticality.

Findings

Gd3+ ESR detects a transition from localized to itinerant Ce 4f electrons.

Near the quantum critical point, localized and itinerant behaviors coexist.

The system exhibits non-Fermi liquid behavior close to the magnetic transition.

Abstract

The CeIn3-xSnx cubic heavy fermion system presents an antiferromagnetic transition at T_N = 10 K, for x = 0, that decreases continuously down to 0 K upon Sn substitution at a critical concentration of x_c ~ 0.65. In the vicinity of T_N -> 0 the system shows non-Fermi liquid behavior due to antiferromagnetic critical fluctuations. For a high Sn content, x > 2.2, intermediate valence effects are present. In this work we show that Gd3+-doped electron spin resonance (ESR) probes a change in the character of the Ce 4f electron, as a function of Sn substitution. The Gd3+ ESR results indicate a transition of the Ce 4f spin behavior from localized to itinerant. Near the quantum critical point, on the antiferromagnetic side of the magnetic phase diagram, both localized and itinerant behaviors coexist.