XPS study of single-crystal (111) UO2 thin film before and after Ar+ etching

International Conference on Nuclear Chemistry

December 08-09, 2016 San Antonio, USA

K E Ivanov, Yu A Teterin, A J Popel, K I Maslakov, A Yu Teterin, S N Kalmykov, R Springell, T B Scott and I Farnan

NRC â�?�?Kurchatov Instituteâ�?, Russia
Lomonosov Moscow State University, Russia
Imperial College London, UK
University of Bristol, UK
University of Cambridge, UK

Posters & Accepted Abstracts: J Nucl Med Radiat Ther

Abstract :

X-ray photoelectron spectroscopy was employed for determination of the oxygen coefficient k0 = 2+x and ionic (U4+, U5+ and U6+) composition k(%) of oxides UO2+x formed on the surface of the UO2 (111) thin film on YSZ (yttria-stabilised zirconia) substrates (111) before and after the Ar+ etching. The oxygen coefficient and ionic composition of the sample surface was found on the basis of the core U 4f and O 1s intensities, as well as on the basis of the U 5f relative intensity. It was found that interaction of the single crystall UO2 film with atmospheric air leads to formation on the surface (several nm) of oxide UO2.19, whose ionic composition is: 18% of U4+, 61% of U5+ and 21% of U6+. The 20 second Ar+ etching leads to formation of oxide UO2.12, the 180 second Ar+ etching leads to formation of oxide UO2.11. It was established that after the Ar+ etching the UO2.12 structure self-reorganizes on the surface. This follows from the high-intensity (~30% of the basic peak intensity) shake-up satellites at 6.9 eV from the basic peak in the XPS spectra.

Biography :

Email: ivanov_ke@nrcki.ru