Spectral Change in 3d-4f Resonant Inelastic X-ray Scattering of Ce Intermetallics Across the Transition between Kondo Singlet and Localized-Spin State

The spectral change in the 3d resonant X-ray inelastic scattering (RIXS) induced by the spin-state transition between Kondo singlet (KS) and localized spin (LS) state is theoretically investigated for γ-like Ce intermetallics by means of a single impurity Anderson model. The basis configurations with an electron-hole pair are included in the calculation within the configuration interaction scheme, in addition to the intra-atomic full multiplet coupling of the Ce impurity. A distinct spectral change is found across the KS-LS transition in the RIXS excited at the charge-transfer satellite of the 3d X-ray absorption spectrum (XAS) under a polarized geometry. In contrast, the 3d XAS and RIXS spectra under a depolarized geometry are rather insensitive to the spin-state transition.