Probing Covalency in the UO3 Polymorphs by U M4 edge HR- XANES

16th International Conference on X-ray Absorption Fine Structure

Podkovyrina, Y.^1 ; Pidchenko, I.^2 ; Prüßmann, T.^2 ; Bahl, S.^2 ; Göttlicher, J.^3 ; Soldatov, A.^1 ; Vitova, T.^2

Internatonal Research Center Smart Materials, Southern Federal University, ul. Zorge 5, Rostov-on-Don

344090, Russia^1

Karlsruhe Institute of Technology, Insitute for Nuclear Waste Disposal, P.O. Box 3640, Karlsruhe

D-76021, Germany^2

Karlsruhe Institute of Technology, ANKA Synchrotron Radiation Facility, P.O. Box 3640, Karlsruhe

D-76021, Germany^3

关键词: Calculated spectrum;    Crystalline phasis;    Finger print;    Full-multiple scattering theory;    Input parameter;    Polymorphic phasis;    Theoretical calculations;    XANES spectra;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012092/pdf
DOI  :  10.1088/1742-6596/712/1/012092

来源: IOP

【 摘 要 】

Local atomic and electronic structure investigations of uranium trioxide (UO3) crystalline phases performed by the U M4edge HR-XANES technique is presented. The experimental U M4edge HR-XANES spectra of α-UO3, β-UO3and γ-UO3polymorphic phases are compared with spectra of uranate (CaU2O7) and uranyl (UO3•1-2(H2O)) compounds. We describe a finger print approach valuable for characterization of variations of U-O axial bond lengths. Theoretical calculations of spectra using full-multiple-scattering theory (FEFF9.6 code) are performed. We have tested and selected input parameters, which provide best agreement between experimental and calculated spectra.