title: Investigation of the Fe K-edge XANES spectra from Fe(1-x)Ga(x)SbO4: local versus nonlocal excitations.
abstract: The Fe K-edge X-ray absorption near-edge (XANES) spectra from Fe(1-x)Ga(x)SbO(4), having a rutile-like structure, have been investigated. Similar to the Ti K-edge XANES spectrum from TiO(2) (rutile), the low-energy pre-edge region observed in the Fe K-edge spectra is too broad to be representative of only a local, quadrupolar 1s → 3d excitation. The broadness of this peak results from the presence of a nonlocal transition, referred to as an intersite hybrid, which involves the excitation of 1s electrons to unoccupied 3d states of a next-nearest-neighbor Fe atom. (These 3d states overlap Fe 4p states of the absorbing atom through O 2p states.) With increasing Ga concentration, the intensity of the intersite hybrid peak decreases because of a deficiency of unoccupied next-nearest-neighbor 3d states. This observation provides important information on how the peak intensities of these nonlocal excitations are affected by substitution of the constituent elements.
authors.affiliation: Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Sigrist
authors.forename: Michael W
authors.initials: MW
authors.lastname: Gaultois
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Grosvenor
mesh_terms: D000965:Antimony / Q000737:chemistry*; D005708:Gallium / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D010087:Oxides; C091696:antimony oxide; D000965:Antimony; D005708:Gallium; D007501:Iron