RIXS at the cerium L₃-edge of Ce(III) and Ce(IV) systems: some observations

Abstract

We report recent observations of resonant inelastic X-ray scattering (RIXS) at the cerium L3-edge of CePO4, CeO2, and Ce3+ ion in aqueous solution. The intensity of the emission spectrum, including the dispersive Raman below the edge and the emerging nondispersive fluorescence above the edge, was recorded with a solid-state detector with low-energy resolution and a WDX detector with modestly high-energy resolution. The yield of the emission was used to monitor the cerium L3-edge X-ray absorption near edge structures (XANES) in a constant initial state (CIS) mode as the photon energy sweeps across the cerium L3-edge. The CIS XANES is compared with the XANES recorded using the nondispersive fluorescence yield, Lα, in a constant final state (CFI) mode. It is found that the Raman yield dominates the total emission in the pre-edge region and diminishes rapidly at threshold. The RIXS of Ce3+ in aqueous solution exhibits similar behavior as CePO4. The post-whiteline RIXS intensity of CePO4 exhibits a correlation with excitation energy. CeO2 also exhibits a less intense whiteline in CIS XANES compared with the XANES detected with normal fluorescence. The implications of these observations with improved instrumental resolution are noted.

Electronic properties of epitaxial cerium oxide films during controlled reduction and oxidation studied by resonant inelastic X-ray scattering

“…16,17 The technique has been shown to be suitable to investigate charge localization/delocalization on oxide based systems with element and electronic level sensitivity. 8,[18][19][20] In particular, Ce L 3 -edge XANES spectra are extremely sensitive to the electronic configuration in cerium oxide based materials. 21,22 The main edge is split into two components due to many body effects, specifically to screened and unscreened transitions to the 5d band.…”