Geometry of α-Cr2O3(0001) as a function of H2O partial pressure

DOI: 10.1021/acs.jpcc.5b04607

Authors: Mahmoud Ahmed (The University of Manchester) , Xavier Torrelles (Instituto de Ciencia de Materiales de Barcelona-CSIC) , Jon Treacy (The University of Manchester) , Hadeel Hussain (University College London) , Chris Nicklin (Diamond Light Source) , Paul L. Wincott (The University of Manchester) , David J. Vaughan (The University of Manchester) , Geoff Thornton (University College London) , Robert Lindsay (The University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry C , VOL 119 (37)

State: Published (Approved)
Published: August 2015
Diamond Proposal Number(s): 7622

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 by ab initio calculations, which may be a result of some differences between the experimental conditions and those modeled.

Diamond Keywords: Alloys

Subject Areas: Chemistry, Materials, Physics


Instruments: I07-Surface & interface diffraction

Added On: 07/09/2015 16:18

Documents:
acs.jpcc.5b04607.pdf

Discipline Tags:

Surfaces Physics Physical Chemistry Chemistry Corrosion Materials Science Metallurgy

Technical Tags:

Diffraction