AVS 59th Annual International Symposium and Exhibition
    Actinides and Rare Earths Focus Topic Tuesday Sessions
       Session AC+EN-TuM

Paper AC+EN-TuM10
XPS Study of Uranium Oxides with Various Precipitating Agents

Tuesday, October 30, 2012, 11:00 am, Room 006

Session: Energetic Materials Issues for Nuclear Power: Fuels, Corrosion and Waste Disposal
Presenter: K.S. Holliday, Lawrence Livermore National Laboratory
Authors: K.S. Holliday, Lawrence Livermore National Laboratory
J. Plaue, University of Nevada, Las Vegas
W.J. Siekhaus, Lawrence Livermore National Laboratory
A.J. Nelson, Lawrence Livermore National Laboratory
Correspondent: Click to Email
X-ray photoemission spectroscopy (XPS) and Auger electron spectroscopy (AES) are powerful tools for materials characterization by determining chemical shifts in core level spectra. By combining XPS data with the X-ray excited Auger transitions one is able to have a two dimensional analysis based on both initial state effects and final state relaxation energies. Specifically, combining the chemical shift of the U NOV Auger lines with the chemical shift of the U 4f photoelectron lines defines the Auger parameter (difference in the binding energy of the photoelectron and Auger lines) and results in a reliable method for determining oxidation states independent of calibration. Here, XPS analysis of core-level excitation and X-ray excited Auger transitions were combined to determine the Auger parameter and produce chemical state (or Wagner) plots for various uranium and thorium compounds. In addition this method is combined with valence band spectra to characterize uranium oxides precipitated with different reagents. The calcination of these precipitates is followed at various temperatures in an effort to identify unique characteristics associated with the precipitating reagent.