title: Magnetite, a model system for mixed-valence oxides, does not show charge ordering.
abstract: We have investigated the charge ordering (CO) in magnetite below the Verwey transition. A new set of half-integer and mixed-integer superlattice reflections of the low-temperature phase have been studied by x-ray resonant scattering. None of these reflections show features characteristic of CO. We demonstrate the absence of CO along the c axis with the periodicity of either the cubic lattice q=(001) or the doubled cubic lattice q=(001/2). This result suggests that the Verwey transition is caused by strong electron-phonon interaction instead of an electronic ordering on the octahedral Fe atoms.
authors.affiliation: Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pza. San Francisco s/n 50009 Zaragoza, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Subías
authors.forename: Joaquín
authors.initials: J
authors.lastname: García
authors.forename: Javier
authors.initials: J
authors.lastname: Blasco
authors.forename: M
authors.initials: M
authors.lastname: Grazia Proietti
authors.forename: Hubert
authors.initials: H
authors.lastname: Renevier
authors.forename: M
authors.initials: M
authors.lastname: Concepción Sánchez