Knight Shift Anomalies in Heavy Electron Materials

We calculate nonlinear 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 noncrossing approximation. The $K$ vs $\chi$ nonlinearity diminishes with decreasing Kondo temperature $T_0$ and nuclear-spin–local-moment separation. Treating the Ce ions as an incoherent array in CeS${\mathrm{n}}_3$, we find excellent agreement with the observed Sn $K\left(T\right)$ data.