Knight Shift Anomalies in Heavy Electron Materials

TL;DR

This paper investigates anomalies in the Knight Shift versus susceptibility in heavy electron materials, modeling Ce ions with the Anderson Hamiltonian and comparing theoretical predictions with experimental data.

Contribution

It introduces a detailed calculation of Knight Shift anomalies using the Anderson model and non-crossing approximation, aligning theory with experimental observations in CeSn$_3$.

Findings

Non-linear K vs. χ anomalies decrease with lower Kondo temperature.

The model accurately reproduces experimental Knight Shift data in CeSn$_3$.

The anomalies are influenced by the separation between nuclear spins and local moments.

Abstract

We calculate non-linear Knight Shift $K$ vs. susceptibility $\chi$ anomalies for Ce ions possessing local moments in metals. The ions are modeled with the Anderson Hamiltonian and studied within the non-crossing approximation (NCA). The $K-vs.- \chi$ non-linearity diminishes with decreasing Kondo temperature $T_0$ and nuclear spin- local moment separation. Treating the Ce ions as an incoherent array in CeSn$_3$, we find excellent agreement with the observed Sn $K(T)$ data.