title: Sensitivity to actinide doping of uranium compounds by resonant inelastic X-ray scattering at uranium L3 edge.
abstract: Valence-to-core resonant inelastic X-ray scattering (RIXS) and high energy resolution fluorescence detection (HERFD) X-ray absorption measurements were performed at the U L3 edges of UO2 and UO2(NO3)2(H2O)6. The results are compared with model calculations based on the local-density-approximation formalism, taking into account Coulomb interaction U (LDA + U). We show that despite strong 5f-5f electronic correlations in the studied systems and the use of core-level excitations in the intermediate stage of the spectroscopic process, the RIXS technique probes a convolution of the single-particle densities of states in the valence and conduction bands. For UO2, the detected crystal-field splitting between the U 6d eg and t2g orbitals from the RIXS spectra (∼3.5 eV) is larger than that previously derived from optical spectroscopy. Furthermore, by using an example of the U0.75Pu0.25O2 mixed oxide, we show that the RIXS technique at the U L3 edges is sensitive to the substitution of U with other actinide, in contrast to conventional X-ray absorption methods. That is, due to changes in the occupied part rather than in the unoccupied part of the U 6d states caused by the substitution.
authors.affiliation: European Synchrotron Radiation Facility , 6 Rue Jules Horowitz, BP 220, 38043, Grenoble, France.
authors.forename: Kristina O
authors.initials: KO
authors.lastname: Kvashnina
authors.affiliation: European Synchrotron Radiation Facility , 6 Rue Jules Horowitz, BP 220, 38043, Grenoble, France.|Department of Physics and Astronomy, Uppsala University , Box 516, S-751 20 Uppsala, Sweden.
authors.forename: Yaroslav O
authors.initials: YO
authors.lastname: Kvashnin
authors.affiliation: Department of Physics and Astronomy, Uppsala University , Box 516, S-751 20 Uppsala, Sweden.
authors.forename: Johan R
authors.initials: JR
authors.lastname: Vegelius
authors.affiliation: European Synchrotron Radiation Facility , 6 Rue Jules Horowitz, BP 220, 38043, Grenoble, France.
authors.forename: Alexei
authors.initials: A
authors.lastname: Bosak
authors.affiliation: CEA, DEN, DEC, CEN Cadarache , 13108, St. Paul lez Durance, France.
authors.forename: Philippe M
authors.initials: PM
authors.lastname: Martin
authors.affiliation: Department of Physics and Astronomy, Uppsala University , Box 516, S-751 20 Uppsala, Sweden.
authors.forename: Sergei M
authors.initials: SM
authors.lastname: Butorin