Atomic-Scale Determination of Cation Inversion in Spinel-Based Oxide Nanoparticles
Torruella, Pau (Universitat de Barcelona. Departament d'Enginyeria Electrònica i Biomèdica)
Ruiz Caridad, Alicia (Universitat de Barcelona. Departament d'Enginyeria Electrònica i Biomèdica)
Walls, Michael (Paris-Sud University)
Gómez Roca, Alejandro (Institut Català de Nanociència i Nanotecnologia)
López-Ortega, Alberto (CIC nanoGUNE)
Blanco Portals, Javier (Universitat de Barcelona. Departament d'Enginyeria Electrònica i Biomèdica)
López Conesa, Lluís (Universitat de Barcelona. Departament d'Enginyeria Electrònica i Biomèdica)
Nogués, Josep (Institut Català de Nanociència i Nanotecnologia)
Peiro, Francesca (Universitat de Barcelona. Departament d'Electrònica)
Estrade, Sonia (Universitat de Barcelona. Departament d'Electrònica)

Date:	2018
Abstract:	The atomic structure of nanoparticles can be easily determined by transmission electron microscopy. However, obtaining atomic-resolution chemical information about the individual atomic columns is a rather challenging endeavor. Here, crystalline monodispersed spinel FeO/MnO core-shell nanoparticles have been thoroughly characterized in a high-resolution scanning transmission electron microscope. Electron energy-loss spectroscopy (EELS) measurements performed with atomic resolution allow the direct mapping of the Mn/Mn ions in the shell and the Fe/Fe in the core structure. This enables a precise understanding of the core-shell interface and of the cation distribution in the crystalline lattice of the nanoparticles. Considering how the different oxidation states of transition metals are reflected in EELS, two methods of performing a local evaluation of the cation inversion in spinel lattices are introduced. Both methods allow the determination of the inversion parameter in the iron oxide core and manganese oxide shell, as well as detecting spatial variations in this parameter, with atomic resolution. X-ray absorption measurements on the whole sample confirm the presence of cation inversion. These results present a significant advance toward a better correlation of the structural and functional properties of nanostructured spinel oxides.
Grants:	Ministerio de Economía y Competitividad MAT2016-77391-R Ministerio de Economía y Competitividad MAT2016-79455-P Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-292 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-776 Ministerio de Economía y Competitividad IJCI-2014-21530 European Commission 312483 Ministerio de Economía y Competitividad SEV-2013-0295
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Magnetic nanoparticles ; EELS ; Core−shell ; Spinel ; Cation inversion
Published in:	Nano letters, Vol. 18, Issue 9 (September 2018) , p. 5854-5861, ISSN 1530-6992

DOI: 10.1021/acs.nanolett.8b02524
PMID: 30165026

Preprint 30 p, 2.4 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles