title: EXAFS study of the Fex/ZrO2 composite nanomaterials obtained by sol-gel synthesis.
abstract: The local Zr and Fe arrangements in the nanocomposite system Fe(x)/ZrO2 (x=0-0.2) obtained by sol-gel method were studied by EXAFS. The phase composition was found to vary significantly on iron loading. For the samples calcined at 500 or 600 degrees C, at x< or =0.01, the formed ZrO2 is a mixture of monoclinic and tetragonal structures. Only tetragonal structure is revealed at x > or = 0.05 with the exception of Fe0.2/ZrO2, calcined at 500 degrees C, where new non-typically short Zr-Zr distances (3.29, 3.43A) were observed. At low iron loading (less than one monolayer) Fe3+ ions were found to localize within the pre-surface layers of ZrO2 nanoparticles showing property of isolated ions. For greater Fe loading, iron exhibits either two-dimensional layer structure or two-phase system.
authors.affiliation: Boreskov Institute of Catalysis, Novosibirsk, Russia. kriven@inp.nsk.su
authors.forename: V
authors.initials: V
authors.lastname: Kriventsov
authors.forename: D
authors.initials: D
authors.lastname: Kochubey
authors.forename: J A
authors.initials: JA
authors.lastname: Navio
authors.forename: M C
authors.initials: MC
authors.lastname: Hidalgo
authors.forename: G
authors.initials: G
authors.lastname: Colón
authors.forename: M
authors.initials: M
authors.lastname: Tsodikov
authors.forename: Y
authors.initials: Y
authors.lastname: Maksimov
authors.forename: I
authors.initials: I
authors.lastname: Suzdalev