Combining X-Ray Whole Powder Pattern Modeling, Rietveld and Pair Distribution Function Analyses as a Novel Bulk Approach to Study Interfaces in Heteronanostructures : Oxidation Front in FeO/Fe3O4 Core/Shell Nanoparticles as a Case Study
Ichikawa, Rodrigo U. (IPEN-Instituto de Pesquisas Energéticas e Nucleares)
Gómez Roca, Alejandro (Institut Català de Nanociència i Nanotecnologia)
López-Ortega, Alberto (CIC nanoGUNE)
Estrader, Marta (Institut Català de Nanociència i Nanotecnologia)
Peral Alonso, Inmaculada (ALBA Laboratori de Llum de Sincrotró)
Turrillas, Xabier (ALBA Laboratori de Llum de Sincrotró)
Nogués, Josep (Institut Català de Nanociència i Nanotecnologia)

Data:	2018
Resum:	Understanding the microstructure in heterostructured nanoparticles is crucial to harnessing their properties. Although microscopy is ideal for this purpose, it allows for the analysis of only a few nanoparticles. Thus, there is a need for structural methods that take the whole sample into account. Here, a novel bulk-approach based on the combined analysis of synchrotron X-ray powder diffraction with whole powder pattern modeling, Rietveld and pair distribution function is presented. The microstructural temporal evolution of FeO/FeO core/shell nanocubes is studied at different time intervals. The results indicate that a two-phase approach (FeO and FeO) is not sufficient to successfully fit the data and two additional interface phases (FeO and FeO) are needed to obtain satisfactory fits, i. e. , an onion-type structure. The analysis shows that the FeO phases grow to some extent (≈1 nm) at the expense of the FeO core. Moreover, the FeO core progressively changes its stoichiometry to accommodate more oxygen. The temporal evolution of the parameters indicates that the structure of the FeO/FeO nanocubes is rather stable, although the exact interface structure slightly evolves with time. This approach paves the way for average studies of interfaces in different kinds of heterostructured nanoparticles, particularly in cases where spectroscopic methods have some limitations.
Ajuts:	Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-292 Ministerio de Economía y Competitividad MAT2016-77391-R Ministerio de Economía y Competitividad IJCI-2014-21530 Ministerio de Economía y Competitividad MAT2015-67593-P Ministerio de Economía y Competitividad BIA2014-57658-C2-1-R Ministerio de Economía y Competitividad SEV-2013-0295
Nota:	Altres ajuts: Beatriu de Pinos Program (2011 BPB 00209)
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Matèria:	Core/shell nanoparticles ; Interfaces ; Iron oxides ; Pair distribution function ; Rietveld ; Whole powder pattern modeling ; X-ray diffraction
Publicat a:	Small, Vol. 14, Issue 30 (July 2018) , art. 1800804, ISSN 1613-6829

DOI: 10.1002/smll.201800804

Preprint 43 p, 3.3 MB

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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > Institut Català de Nanociència i Nanotecnologia (ICN2)
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