Structural perturbations of epitaxial α-(Fe1-xVx)2O3 thin films driven by excess oxygen near the surface

S. E. Chamberlin, T. C. Kaspar, M. E. Bowden, V. Shutthanandan, B. Kabius, S. Heald, D. J. Keavney, S. A. Chambers

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Abstract

We examine the structure and composition of phase-pure epitaxial α-(Fe1-xVx)2O3 thin films deposited on α-Al2O3(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.

Original languageEnglish (US)
Article number233702
JournalJournal of Applied Physics
Volume116
Issue number23
DOIs
StatePublished - Dec 21 2014

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Chamberlin, S. E., Kaspar, T. C., Bowden, M. E., Shutthanandan, V., Kabius, B., Heald, S., Keavney, D. J., & Chambers, S. A. (2014). Structural perturbations of epitaxial α-(Fe1-xVx)2O3 thin films driven by excess oxygen near the surface. Journal of Applied Physics, 116(23), [233702]. https://doi.org/10.1063/1.4903839