Correction for 'Mixed HO/H plasma-induced redox reactions of thin uranium oxide films under UHV conditions' by Ghada El Jamal , , 2021, DOI: 10.1039/d1dt01020d.
View Article and Find Full Text PDFX-ray photoelectron spectroscopy (XPS) has been used to study the effect of mixed HO/H gas plasma on the surfaces of UO, UO and UO thin films at 400 °C. The experiments were performed under ultra-high vacuum conditions. Deconvolution of the U4f 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 H concentration in the feed gas of the plasma.
View Article and Find Full Text PDFThin UO films exposed to water plasma under UHV conditions have been shown to be interesting models for radiation induced oxidative dissolution of spent nuclear fuel. This is partly attributed to the fact that several of the reactive oxidizing and reducing species in a water plasma are also identified as products of radiolysis of water. Exposure of UO films to water plasma has previously been shown to lead to oxidation from U(iv) to U(v) and (vi).
View Article and Find Full Text PDFThin films of UO2, U2O5, and UO3 were prepared in situ and exposed to reactive gas plasmas of O2, H2 and H2O vapour produced with an ECR plasma source (electron cyclotron resonance) under UHV conditions. The plasma constituents were analysed using a residual gas analyser mass spectrometer. For comparison, the thin films were also exposed to the plasma precursor gases under comparable conditions.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2020
Our present understanding of surface dissolution of nuclear fuels such as uranium dioxide (UO) is limited by the use of nonlocal characterization techniques. Here we discuss the use of state-of-the-art scanning transmission electron microscopy (STEM) to reveal atomic-scale changes occurring to a UO thin film subjected to anoxic dissolution in deionized water. No amorphization of the UO film surface during dissolution is observed, and dissolution occurs preferentially at surface reactive sites that present as surface pits which increase in size as the dissolution proceeds.
View Article and Find Full Text PDFIntrinsic properties of a compound (e.g., electronic structure, crystallographic structure, optical and magnetic properties) define notably its chemical and physical behavior.
View Article and Find Full Text PDFWe describe a method to produce U2O5 films in situ using the Labstation, a modular machine developed at JRC Karlsruhe. The Labstation, an essential part of the Properties of Actinides under Extreme Conditions laboratory (PAMEC), allows the preparation of films and studies of sample surfaces using surface analytical techniques such as X-ray and ultra-violet photoemission spectroscopy (XPS and UPS, respectively). All studies are made in situ, and the films, transferred under ultra-high vacuum from their preparation to an analyses chamber, are never in contact with the atmosphere.
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