Description:
Subject: The interaction of thin films of different actinide oxides with adsorbed water ice was studied by ultraviolet and X-ray photoelectron spectroscopy (UPS and XPS, respectively). Aim: The studies address radiation enhanced reactions, occurring at the actinide oxide surfaces in contact with an aqueous phase under UV-irradiation. This reaction was observed for PuO2 in 2010 and then extended to other actinide oxide surfaces (NpO2, UO3, UPuO2, UThO2). The thin films were produced by reactive sputter deposition from metal targets in an Ar/O2 plasma. Water was condensed as a thick ice overlayer on the surface at low temperature. Subsequent warming led to desorption of the ice and a reduction of the uppermost surface under irradiation by UV-light (from HeI and HeII radiation used for UPS). The observed surface reduction for the materials was tentatively explained as a photoactivated reaction of the surface with the surrounding water phase.
Data: This collection comprises of these datasets: – UPuO2 reduction with water ice
(Ice on U-Pu Oxide Films) – NpO2 reduction with water ice (Ice on Np Oxide Films) – UO3 reduction with water ice
(Ice on UO2 and UO3 Oxide Films) – UThO2 reduction with water ice (Ice on U-Th Oxide Films) In each dataset, you will find a Lab Book together with the spectra data stored in the VAMAS format. This is a universal form used by many commercial data analysis programs such as CasaXPS. Description of the VAMAS format can be found in the internet. See e.g. https://github.com/Yohko/importtool/blob/master/Igor%20Procedures/import%20tool/import_VAMAS.ipf For easier accessibility, you will also find a zip file for each dataset.
Part of the data sets was used for the following publications: P. Cakir, R. Eloirdi, F. Huber, R.J.M. Konings, T. Gouder, Surface reduction of neptunium dioxide and uranium mixed oxides with plutonium and thorium by photocatalytic reaction with ice, Journal of Physical Chemistry C, 119 (2015) 1330-1337.
T. Gouder, A.B. Shick, F. Huber, Surface interaction of PuO2, UO2+x and UO3 with water ice, Topics in Catalysis, 56 (2013) 1112-1120.
Goal: study the reaction of H2O ice overlayers with UO2+x under light and in the dark. Implementation: Deposit thin films of UO2 on Si(111) substrates. Deposition is done by react...
Goal: study the reaction of H2O ice overlayers with UThOx under light and in the dark. Implementation: Thin films of UThOx were prepared by codeposition from Th and U target on a ...
The surface reduction of films of the mixed oxide of uranium U−Pu−O2 with adsorbed water ice was studied by ultraviolet and X-ray photoelectron spectroscopy (UPS and XPS, respectiv...
The surface reductions of films of neptunium dioxide (NpO2) with adsorbed water ice was studied by ultraviolet and X-ray photoelectron spectroscopy (UPS and XPS, respectively). The...