Aleksej J. Popel

XPS Study of Ion Irradiated and Unirradiated UO2 Thin Films

XPS determination of the oxygen coefficient kO = 2 + x and ionic (U(4+), U(5+), and U(6+)) composition of oxides UO2+x formed on the surfaces of differently oriented (hkl) planes of thin UO2 films on LSAT (Al10La3O51Sr14Ta7) and YSZ (yttria-stabilized zirconia) substrates was performed. The U 4f and O 1s core-electron peak intensities as well as the U 5f relative intensity before and after the (129)Xe(23+) and (238)U(31+) irradiations were employed. It was found that the presence of uranium dioxide film in air results in formation of oxide UO2+x on the surface with mean oxygen coefficients kO in the range 2.07-2.11 on LSAT and 2.17-2.23 on YSZ substrates. These oxygen coefficients depend on the substrate and weakly on the crystallographic orientation. On the basis of the spectral parameters it was established that uranium dioxide films AP2,3 on the LSAT substrates have the smallest kO values, and from the XRD and EBSD results it follows that these samples have a regular monocrystalline structure. The XRD and EBSD results indicate that samples AP5-7 on the YSZ substrates have monocrystalline structure; however, they have the highest kO values. The observed difference in the kO values was probably caused by the different nature of the substrates: the YSZ substrates provide 6.4% compressive strain, whereas (001) LSAT substrates result only in 0.03% tensile strain in the UO2 films. (129)Xe(23+) irradiation (92 MeV, 4.8 × 10(15) ions/cm(2)) of uranium dioxide films on the LSAT substrates was shown to destroy both long-range ordering and uranium close environment, which results in an increase of uranium oxidation state and regrouping of oxygen ions in uranium close environment. (238)U(31+) (110 MeV, 5 × 10(10), 5 × 10(11), 5 × 10(12) ions/cm(2)) irradiations of uranium dioxide films on the YSZ substrates were shown to form the lattice damage only with partial destruction of the long-range ordering.

Research data supporting the publication: 'Structural effects in UO

Project: PhD work by A.J. Popel: ‘The effect of radiation damage by fission fragments on the structural stability and dissolution of the UO2 fuel matrix’. The Excel file ‘XRD_UO2_films_YSZ’ with raw XRD data supporting Figures 5, 6 and 7 in the publication: A.J. Popel, A.M. Adamska, P.G. Martin, O.D. Payton, G.I. Lampronti, L. Picco, L. Payne, R. Springell, T.B. Scott, I. Monnet, C. Grygiel, I. Farnan, Structural effects in UO2 thin films irradiated with U ions, Nucl. Instr. and Meth. in Phys. Res. B 386 (2016) 8-15, https://doi.org/10.1016/j.nimb.2016.09.019. The XRD analysis was performed to assess crystallographic structure of the as-produced and irradiated thin films of UO2 on YSZ substrates. The data were generated in June-July 2014 at the Department of Earth Sciences, University of Cambridge, Cambridge, UK. A D8 Bruker diffractometer equipped with a primary Ge monochromator for Cu Ka1 and a Sol-X solid state detector operating in standard Bragg-Brentano geometry was used for the analysis. The samples were spun during signal collection and a zero-background sample holder was used in all cases. The data can be accessed through the University of Cambridge Data Repository.

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Project: PhD work by A.J. Popel: ‘The effect of radiation damage by fission fragments on the structural stability and dissolution of the UO2 fuel matrix’. The Excel file ‘XRD_UO2_films_LSAT’ with raw XRD data supporting Figure 10 and XRD results in the publication: A.J. Popel, V.A. Lebedev, P.G. Martin, A.A. Shiryaev, G.I. Lampronti, R. Springell, S.N. Kalmykov, T.B. Scott, I. Monnet, C. Grygiel, I. Farnan, Structural effects in UO2 thin films irradiated with fission-energy Xe ions, J. Nucl. Mater. 482 (2016) 210-217, https://doi.org/10.1016/j.jnucmat.2016.10.024. The XRD analysis was performed to assess crystallographic structure of the as-produced and irradiated thin films of UO2 on LSAT substrates. The data were generated in June-July 2014 at the Department of Earth Sciences, University of Cambridge, Cambridge, UK. A D8 Bruker diffractometer equipped with a primary Ge monochromator for Cu Ka1 and a Sol-X solid state detector operating in standard Bragg-Brentano geometry was used for the analysis. The samples were spun during signal collection and a zero-background sample holder was used in all cases. The data can be accessed through the University of Cambridge Data Repository.

thin films irradiated with U ions'

Project: PhD work by A.J. Popel: ‘The effect of radiation damage by fission fragments on the structural stability and dissolution of the UO2 fuel matrix’. The Excel file ‘XRD_CeO2’ with raw XRD data supporting the CeO2 powder XRD results The Text files ‘sample1_wt’ and ‘sample2_wt’ with raw EPMA data supporting the EPMA analysis of the two bulk CeO2 samples The Excel file ‘ICP-MS data’ with output ICP-MS data and calculations for water and acid dilutions supporting Figures 5 and 6 and ICP-MS results in the publication: A.J. Popel, S. Le Solliec, G.I. Lampronti, J. Day, P.K. Petrov, I. Farnan, The effect of fission-energy Xe ion irradiation on the structural integrity and dissolution of the CeO2 matrix, J. Nucl. Mater. 484 (2017) 332-338, https://doi.org/10.1016/j.jnucmat.2016.10.046. The XRD analysis was performed to verify the identity of the as-supplied bulk samples and check for other phases. The data were generated on the 5th of June 2014 at the Department of Earth Sciences, University of Cambridge, Cambridge, UK. A bulk sample of the as-supplied CeO2 was powdered using mortar and pestle and analysed on a D8 Bruker diffractometer equipped with a primary Ge monochromator for Cu Ka1 and a Sol-X solid state detector operating in standard Bragg-Brentano geometry. The sample was spun during signal collection and a zero-background sample holder was used. The EPMA analysis was performed to check the composition of the as-supplied bulk samples. The data were generated on the 3rd of July 2014 at the Department of Earth Sciences, University of Cambridge, Cambridge, UK. Prior to the analysis, the samples were embedded in a resin, polished and carbon coated to ensure conductivity for the analysis using a Cameca SX-100 electron microprobe analyser. Calibration of the equipment was performed using a set of rare earth elements. The ICP-MS analysis was performed to measure 140Ce concentration in the extracted solutions. The data were generated on the 23rd of July 2014 at the Department of Earth Sciences, University of Cambridge, Cambridge, UK, on a Perkin Elmer SCIEX Elan DRC II quadrupole ICP-MS. The data can be accessed through the University of Cambridge Data Repository.

Research data supporting the publication: 'Structural effects in UO

Project: PhD work by A.J. Popel: ‘The effect of radiation damage by fission fragments on the structural stability and dissolution of the UO2 fuel matrix’. The Excel file ‘U_ICP-MS data’ with output ICP-MS data and calculations for water and acid dilutions supporting Figures 2 and 3 and ICP-MS results in the publication: A.J. Popel, V.G. Petrov, V.A. Lebedev, J. Day, S.N. Kalmykov, R. Springell, T.B. Scott, I. Farnan, The effect of fission-energy Xe ion irradiation on dissolution of UO2 thin films, J. Alloys Compd. 721 (2017) 586-592, https://doi.org/10.1016/j.jallcom.2017.05.084. The ICP-MS analysis was performed to measure 238U concentration in the extracted solutions. The data were generated on the 13-14th of October 2014 at the Department of Earth Sciences, University of Cambridge, Cambridge, UK, on a Perkin Elmer SCIEX Elan DRC II quadrupole ICP-MS. The data can be accessed through the University of Cambridge Data Repository.