XPS determination of uranium oxidation states
Article first published online: 5 OCT 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Surface and Interface Analysis
Volume 43, Issue 13, pages 1549–1560, December 2011
How to Cite
Ilton, E. S. and Bagus, P. S. (2011), XPS determination of uranium oxidation states. Surf. Interface Anal., 43: 1549–1560. doi: 10.1002/sia.3836
- Issue published online: 10 NOV 2011
- Article first published online: 5 OCT 2011
- Manuscript Accepted: 19 AUG 2011
- Manuscript Revised: 18 AUG 2011
- Manuscript Received: 16 JUN 2011
- oxidation states
This contribution is both a review of different aspects of X-ray photoelectron spectroscopy that can help one determine U oxidation states and a personal perspective on how to effectively model the X-ray photoelectron spectroscopy of complicated mixed-valence U phases. After a discussion of the valence band, the focus lingers on the U4f region, where the use of binding energies, satellite structures, and peak shapes is discussed in some detail. Binding energies were shown to be very dependent on composition/structure and consequently unreliable guides to oxidation state, particularly where assignment of composition is difficult. Likewise, the spin orbit split 4f7/2 and 4f5/2 peak shapes do not carry significant information on oxidation states. In contrast, both satellite-primary peak binding energy separations, as well as intensities to a lesser extent, are relatively insensitive to composition/structure within the oxide–hydroxide–hydrate system and can be used to both identify and help quantify U oxidation states in mixed valence phases. An example of the usefulness of the satellite structure in constraining the interpretation of a complex multivalence U compound is given. Copyright © 2011 John Wiley & Sons, Ltd.