Title

Surface electronic structure and chemisorption on corundum transition-metal oxides: V2O3

Document Type

Article

Publication Date

1-1-1983

Abstract

The surface electronic structure of single-crystal V2O3 has been studied by using ultraviolet and x-ray photoelectron spectroscopy. Both nearly-perfect surfaces and surfaces containing point defects have been prepared, and the influence of O2 and H2O on both types of surfaces has been investigated. Cation core-level spectra from cleaved surfaces exhibit complex structure. The surface electronic band structure is similar to that of the bulk; at room temperature, V2O3 is metallic with the Fermi level EF lying within the overlapping V(3d) a1g and eg conduction bands. A minimum in the density of states occurs between the V(3d) and O(2p) bands at 3 eV below EF. The O(2p) valence band has a width of 5.5-6 eV. Surface defects produced by Ar+-ion bombardment are associated with O vacancies and a net charge transfer to V(3d) levels. O2 interacts strongly with both perfect surfaces and surface defects, transferring charge out of the V(3d) levels and bending both valence and conduction bands up at the surface. The work function rises dramatically, indicating the presence of a negatively charged adsorbed species (likely O2-). H2O adsorbs dissociatively on both cleaved and bombarded surfaces, producing adsorbed OH- radicals with a saturation coverage of less than 0.5 monolayer. © 1983 The American Physical Society.

Publication Source (Journal or Book title)

Physical Review B

First Page

6699

Last Page

6706

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