Structural perturbations of epitaxial α-(Fe{sub 1−x}V{sub x}){sub 2}O{sub 3} thin films driven by excess oxygen near the surface

Journal Article · Sun Dec 21 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4903839· OSTI ID:22402808

Chamberlin, S. E.; Kaspar, T. C.; Bowden, M. E.; Shutthanandan, V.; Kabius, B. ^[1]; Heald, S.; Keavney, D. J. ^[2]

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1. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)
2. Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

We examine the structure and composition of phase-pure epitaxial α-(Fe{sub 1−x}V{sub x}){sub 2}O{sub 3} thin films deposited on α-Al{sub 2}O{sub 3}(0001) substrates by oxygen-plasma-assisted molecular beam epitaxy for 0 ≤ x ≤ ∼0.5. The films crystallize in the corundum lattice, with vanadium substituting for iron throughout. Vanadium cations exhibit the expected 3+ charge state in the bulk, but exhibit higher valences nearer to the surface, most likely because of excess oxygen in interstitial sites near the surface. The extent of vanadium oxidation beyond the 3+ state is inversely proportional to x. The gradation of vanadium valence with depth has an impact on local bonding geometries, and could be highly significant in this material's efficiency as a photocatalyst.

• OSTI ID: 22402808
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM OXIDES
CATIONS
CHARGE STATES
CORUNDUM
IRON
MOLECULAR BEAM EPITAXY
OXYGEN
PERTURBATION THEORY
SUBSTRATES
SURFACES
THIN FILMS
VALENCE
VANADIUM