Crystal-field and Kondo-scale investigations of CeMIn5 (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 CeMIn5 with M=Rh, Ir, and Co to determine the crystal-field scheme and characteristic Kondo temperatures T* 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,M-5 edge and the crystal-field splittings from INS. The characteristic temperature T* has been determined from the line widths of the neutron scattering data. We find that the quasielastic linewidths of the superconducting compounds CeCoIn5 and CeIrIn5 are comparable with the low-energy crystal-field splitting.