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Title: Oxygen vacancy ordering within anion-deficient Ceria

Abstract

The structural properties of anion deficient ceria, CeO{sub 2-{delta}}, have been studied as a function of oxygen partial pressure, p(O{sub 2}), over the range 0>=log{sub 10p}(O{sub 2})>=-18.9 at 1273(2) K using the neutron powder diffraction technique. Rietveld refinement of the diffraction data collected on decreasing p(O{sub 2}) showed increases in the cubic lattice parameter, a, the oxygen nonstoichiometry, delta, and the isotropic thermal vibration parameters, u{sub Ce} and u{sub O}, starting at log{sub 10p}(O{sub 2}){approx}-11. The increases are continuous, but show a distinct kink at log{sub 10p}(O{sub 2}){approx}-14.5. Analysis of the total scattering (Bragg plus diffuse components) using reverse Monte Carlo (RMC) modelling indicates that the O{sup 2-} vacancies preferentially align as pairs in the <111> cubic directions as the degree of nonstoichiometry increases. This behaviour is discussed with reference to the chemical crystallography of the CeO{sub 2}-Ce{sub 2}O{sub 3} system at ambient temperature and, in particular, to the nature of the long-range ordering of O{sup 2-} vacancies within the crystal structure of Ce{sub 7}O{sub 12}. - Graphical abstract: Partial radial distribution function for oxygen vacancies within CeO{sub 1.710} at 1273 K (solid line) showing the increased tendency for local ordering in <111> directions compared to a random distribution (dashedmore » line).« less

Authors:
 [1]; ;  [1];  [2];  [3];  [3]
  1. ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)
  2. Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden)
  3. School of Chemistry, Edinburgh University, The King's Building, West Mains Road, Edinburgh EH9 3JJ (United Kingdom)
Publication Date:
OSTI Identifier:
21372351
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 182; Journal Issue: 10; Other Information: DOI: 10.1016/j.jssc.2009.07.044; PII: S0022-4596(09)00354-5; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AMBIENT TEMPERATURE; ANIONS; CERIUM OXIDES; CRYSTALLOGRAPHY; CUBIC LATTICES; DIFFUSE SCATTERING; MONTE CARLO METHOD; NEUTRON DIFFRACTION; OXYGEN; OXYGEN IONS; PARTIAL PRESSURE; SIMULATION; SPATIAL DISTRIBUTION; VACANCIES; CALCULATION METHODS; CERIUM COMPOUNDS; CHALCOGENIDES; CHARGED PARTICLES; COHERENT SCATTERING; CRYSTAL DEFECTS; CRYSTAL LATTICES; CRYSTAL STRUCTURE; DIFFRACTION; DISTRIBUTION; ELEMENTS; IONS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; POINT DEFECTS; RARE EARTH COMPOUNDS; SCATTERING; THERMODYNAMIC PROPERTIES

Citation Formats

Hull, S, Norberg, S T, Ahmed, I, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Eriksson, S G, Marrocchelli, D, Madden, P A, and Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH. Oxygen vacancy ordering within anion-deficient Ceria. United States: N. p., 2009. Web. doi:10.1016/j.jssc.2009.07.044.
Hull, S, Norberg, S T, Ahmed, I, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Eriksson, S G, Marrocchelli, D, Madden, P A, & Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH. Oxygen vacancy ordering within anion-deficient Ceria. United States. https://doi.org/10.1016/j.jssc.2009.07.044
Hull, S, Norberg, S T, Ahmed, I, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Eriksson, S G, Marrocchelli, D, Madden, P A, and Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH. 2009. "Oxygen vacancy ordering within anion-deficient Ceria". United States. https://doi.org/10.1016/j.jssc.2009.07.044.
@article{osti_21372351,
title = {Oxygen vacancy ordering within anion-deficient Ceria},
author = {Hull, S and Norberg, S T and Ahmed, I and Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg and Eriksson, S G and Marrocchelli, D and Madden, P A and Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH},
abstractNote = {The structural properties of anion deficient ceria, CeO{sub 2-{delta}}, have been studied as a function of oxygen partial pressure, p(O{sub 2}), over the range 0>=log{sub 10p}(O{sub 2})>=-18.9 at 1273(2) K using the neutron powder diffraction technique. Rietveld refinement of the diffraction data collected on decreasing p(O{sub 2}) showed increases in the cubic lattice parameter, a, the oxygen nonstoichiometry, delta, and the isotropic thermal vibration parameters, u{sub Ce} and u{sub O}, starting at log{sub 10p}(O{sub 2}){approx}-11. The increases are continuous, but show a distinct kink at log{sub 10p}(O{sub 2}){approx}-14.5. Analysis of the total scattering (Bragg plus diffuse components) using reverse Monte Carlo (RMC) modelling indicates that the O{sup 2-} vacancies preferentially align as pairs in the <111> cubic directions as the degree of nonstoichiometry increases. This behaviour is discussed with reference to the chemical crystallography of the CeO{sub 2}-Ce{sub 2}O{sub 3} system at ambient temperature and, in particular, to the nature of the long-range ordering of O{sup 2-} vacancies within the crystal structure of Ce{sub 7}O{sub 12}. - Graphical abstract: Partial radial distribution function for oxygen vacancies within CeO{sub 1.710} at 1273 K (solid line) showing the increased tendency for local ordering in <111> directions compared to a random distribution (dashed line).},
doi = {10.1016/j.jssc.2009.07.044},
url = {https://www.osti.gov/biblio/21372351}, journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = 10,
volume = 182,
place = {United States},
year = {Thu Oct 15 00:00:00 EDT 2009},
month = {Thu Oct 15 00:00:00 EDT 2009}
}