Files
Document type
ArticleVersion
Accepted versionPublication date
All rights reserved
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/134997
Probing the variability in oxidation states of magnetite nanoparticles by single-particle spectroscopy
Journal Title
Director/Tutor
Additional contribution
Journal ISSN
Volume Title
Abstract
We have studied the electronic and chemical properties of a variety of ensembles of size-and shape-selected Fe3O4 nanoparticles with single-particle sensitivity by means of synchrotron-based X-ray photoemission electron microscopy. The local X-ray absorption spectra reveal that the oxidation states and the amount and type of cations within the individual nanoparticles can show a striking local variability even when the average structural and magnetic parameters of the monodisperse ensembles appear to be compatible with those of conventional homogeneous magnetite nanoparticles. Our results show the key role played by oleic acid concentration in the reaction mixture on the formation and compositional homogeneity within individual nanoparticles. When the concentration of oleic acid is high enough, the nanoparticles are composed of a Fe3O4 core surrounded by a thin gamma-Fe2O3 shell. However, at a low concentration of the fatty acid, the Fe3O4 nanoparticles are likely inhomogeneous with small inclusions of FeO and Fe phases, as a result of an uncontrolled reduction of Fe3+ cations. All the foregoing underlines the importance of combining both advanced synthesis techniques and complementary single-particle investigations performed on a statistically significant number of particles so as to improve the understanding and control over electronic and magnetic phenomena at the nanoscale.
Related resource
Subject
Subject (English)
Citation
Citation
FRAILE RODRÍGUEZ, Arantxa, et al. Probing the variability in oxidation states of magnetite nanoparticles by single-particle spectroscopy. Journal of Materials Chemistry C. 2018. Vol. 6, num. 4, pags. 875-882. ISSN 2050-7526. [consulted: 8 of October of 2026]. Available at: https://hdl.handle.net/2445/134997