title: 3D Visualization of the Iron Oxidation State in FeO/Fe3O4 Core-Shell Nanocubes from Electron Energy Loss Tomography.
abstract: The physicochemical properties used in numerous advanced nanostructured devices are directly controlled by the oxidation states of their constituents. In this work we combine electron energy-loss spectroscopy, blind source separation, and computed tomography to reconstruct in three dimensions the distribution of Fe(2+) and Fe(3+) ions in a FeO/Fe3O4 core/shell cube-shaped nanoparticle with nanometric resolution. The results highlight the sharpness of the interface between both oxides and provide an average shell thickness, core volume, and average cube edge length measurements in agreement with the magnetic characterization of the sample.
authors.affiliation: LENS-MIND-IN2UB, Departament d'Electrònica, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain.
authors.forename: Pau
authors.initials: P
authors.lastname: Torruella
authors.affiliation: Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza , 50018 Zaragoza, Spain.|Fundación ARAID, 50018 Zaragoza, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Arenal
authors.affiliation: Department of Materials Science & Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, United Kingdom.
authors.forename: Francisco
authors.initials: F
authors.lastname: de la Peña
authors.affiliation: CEA-LETI, MINATEC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France.
authors.forename: Zineb
authors.initials: Z
authors.lastname: Saghi
authors.affiliation: LENS-MIND-IN2UB, Departament d'Electrònica, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Yedra
authors.affiliation: LENS-MIND-IN2UB, Departament d'Electrònica, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Eljarrat
authors.affiliation: LENS-MIND-IN2UB, Departament d'Electrònica, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: López-Conesa
authors.affiliation: Laboratoire de Physique et Chimie des Nano-objects , 135 Avenue de Rangueil, 31077 Toulouse Cedex 4, France.
authors.forename: Marta
authors.initials: M
authors.lastname: Estrader
authors.affiliation: INSTM and Dipartimento di Chimica "U. Schiff", Università degli Studi di Firenze , Via della Lastruccia 3, Sesto Fiorentino, I-50019 Firenze, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: López-Ortega
authors.affiliation: Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , 10691 Stockholm, Sweden.
authors.forename: Germán
authors.initials: G
authors.lastname: Salazar-Alvarez
authors.affiliation: Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology , Campus UAB, Bellaterra, 08193 Barcelona, Spain.|ICREA-Institució Catalana de Recerca i Estudis Avançats , Passeig de Lluís Companys, 23, 08010 Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Nogués
authors.affiliation: Department of Materials Science & Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, United Kingdom.
authors.forename: Caterina
authors.initials: C
authors.lastname: Ducati
authors.affiliation: Department of Materials Science & Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, United Kingdom.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Midgley
authors.affiliation: LENS-MIND-IN2UB, Departament d'Electrònica, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain.
authors.forename: Francesca
authors.initials: F
authors.lastname: Peiró
authors.affiliation: LENS-MIND-IN2UB, Departament d'Electrònica, Institut de Nanociència i Nanotecnologia, Universitat de Barcelona , Martí i Franquès 1, E-08028 Barcelona, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Estradé
keywords: EELS; ELNES; Electron tomography; compressed sensing; iron oxide; oxidation states