title: Geometry of α-Cr2O3(0001) as a Function of H2O Partial Pressure.
abstract: Surface X-ray diffraction has been employed to elucidate the surface structure of α-Cr2O3(0001) as a function of water partial pressure at room temperature. In ultra high vacuum, following exposure to ∼2000 Langmuir of H2O, the surface is found to be terminated by a partially occupied double layer of chromium atoms. No evidence of adsorbed OH/H2O is found, which is likely due to either adsorption at minority sites, or X-ray induced desorption. At a water partial pressure of ∼30 mbar, a single OH/H2O species is found to be bound atop each surface Cr atom. This adsorption geometry does not agree with that predicted byab initiocalculations, which may be a result of some differences between the experimental conditions and those modeled.
authors.affiliation: Corrosion and Protection Centre, School of Materials, The University of Manchester , Sackville Street, Manchester, M13 9PL, U.K.
authors.forename: M H M
authors.initials: MH
authors.lastname: Ahmed
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC) , Campus UAB, 08193 Bellaterra, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Torrelles
authors.affiliation: Corrosion and Protection Centre, School of Materials, The University of Manchester , Sackville Street, Manchester, M13 9PL, U.K.
authors.forename: J P W
authors.initials: JP
authors.lastname: Treacy
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, U.K.
authors.forename: H
authors.initials: H
authors.lastname: Hussain
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus , Didcot, Oxfordshire, OX11 0DE, U.K.
authors.forename: C
authors.initials: C
authors.lastname: Nicklin
authors.affiliation: Williamson Research Centre for Molecular Environmental Science and School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, U.K.
authors.forename: P L
authors.initials: PL
authors.lastname: Wincott
authors.affiliation: Williamson Research Centre for Molecular Environmental Science and School of Earth, Atmospheric and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, U.K.
authors.forename: D J
authors.initials: DJ
authors.lastname: Vaughan
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, U.K.
authors.forename: G
authors.initials: G
authors.lastname: Thornton
authors.affiliation: Corrosion and Protection Centre, School of Materials, The University of Manchester , Sackville Street, Manchester, M13 9PL, U.K.
authors.forename: R
authors.initials: R
authors.lastname: Lindsay