Mixed H.sub.2./sub.O/H.sub.2./sub. plasma-induced redox reactions of thin uranium oxide films under UHV conditions

0553324 - FZÚ 2022 RIV GB eng J - Článek v odborném periodiku
El Jamal, G. - Gouder, T. - Eloirdi, R. - Tereshina-Chitrova, Evgenia - Horák, L. - Jonsson, M.
Mixed H₂O/H₂ plasma-induced redox reactions of thin uranium oxide films under UHV conditions.
Dalton Transactions. Roč. 50, č. 36 (2021), s. 12583-12591. ISSN 1477-9226. E-ISSN 1477-9234
Institucionální podpora: RVO:68378271
Klíčová slova: UO₂ * UO_2+x * UO₃ * U₂O₅ * film * XPS * XRD
Obor OECD: Inorganic and nuclear chemistry
Impakt faktor: 4.569, rok: 2021
Způsob publikování: Open access

X-ray photoelectron spectroscopy (XPS) has been used to study the effect of mixed H2O/H2 gas plasma on the surfaces of UO2, U2O5 and UO3 thin films at 400 °C. The experiments were performed in-situ under ultra-high vacuum conditions. Deconvolution of the U4f7/2 peaks into U(iv), U(v) and U(vi) components revealed the surface composition of the films after 10 min plasma exposure as a function of H2 concentration in the feed gas of the plasma. Some selected films (unexposed and exposed) were also analysed using grazing-incidence X-ray diffraction (GIXRD), which revealed a considerable impact of the plasma and heating conditions on the crystal structure of the films in line with the change of the oxidation state. This structural difference is proposed to be the main kinetic barrier for plasma induced transfer between U(iv) and U(v) in both directions.
Trvalý link: http://hdl.handle.net/11104/0328300