title: Effect of surface polishing and oxidization induced strain on electronic order at the Verwey transition in Fe3O4.
abstract: Following the controversy between two previous publications (Lorenzo et al 2008 Phys. Rev. Lett.  101 226401 and Garcia et al 2009 Phys. Rev. Lett.  102 176405), we report on the influence of mechanical polishing, and subsequent sample storage, on the electronic order at the Verwey transition of highly pure magnetite, Fe(3)O(4), by resonant x-ray scattering. Contrary to expectations, mechanically polishing the surface induces an inhomogeneous micron deep dead layer, probably of powdered Fe(3)O(4). In addition, we have found that polishing the sample immediately before the experiment influences and favors the appearance of long range order electronic correlations, whereas samples polished well in advance have their electronic order quenched. Conversely, lattice distortions associated with the Verwey transition appear less affected by the surface state. We conclude that mechanical polishing induces stresses at the surface that may propagate into the core of the single crystal sample. These strains relax with time, which affects the different order parameters, as measured by x-ray resonant diffraction.
authors.affiliation: AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow, Poland. tabis@physics.umn.edu
authors.forename: W
authors.initials: W
authors.lastname: Tabis
authors.forename: J E
authors.initials: JE
authors.lastname: Lorenzo
authors.forename: A
authors.initials: A
authors.lastname: Kozlowski
authors.forename: T
authors.initials: T
authors.lastname: Kolodziej
authors.forename: Z
authors.initials: Z
authors.lastname: Tarnawski
authors.forename: Z
authors.initials: Z
authors.lastname: Kakol
authors.forename: C
authors.initials: C
authors.lastname: Mazzoli
authors.forename: H C
authors.initials: HC
authors.lastname: Walker
authors.forename: N
authors.initials: N
authors.lastname: Jaouen
authors.forename: D
authors.initials: D
authors.lastname: Mannix
authors.forename: C
authors.initials: C
authors.lastname: Marin
authors.forename: J M
authors.initials: JM
authors.lastname: Honig