Crystal-field and Kondo-scale investigations ofCeMIn5(M=Co, Ir, and Rh): A combined x-ray absorption and inelastic neutron scattering study

Linear-polarized soft-x-ray absorption (XAS) and inelastic neutron scattering (INS) experiments have been performed on $\text{Ce}M{\text{In}}_5$ with $M=\text{Rh}$, Ir, and Co to determine the crystal-field scheme and characteristic Kondo temperatures $T^{\ast }$ for the hybridization between $4f$ and conduction electrons. The ground-state wave functions are determined from the polarization-dependent soft-XAS data at the cerium $M_{4,5}$ edge and the crystal-field splittings from INS. The characteristic temperature $T^{\ast }$ has been determined from the line widths of the neutron scattering data. We find that the quasielastic linewidths of the superconducting compounds ${\text{CeCoIn}}_5$ and ${\text{CeIrIn}}_5$ are comparable with the low-energy crystal-field splitting.