Characterization of the iron oxide phases formed during the synthesis of core–shell FexOy@C nanoparticles modified with Ag
- 7 July 2020
- journal article
- research article
- Published by IOP Publishing in Nanotechnology
- Vol. 31 (39), 395703
- https://doi.org/10.1088/1361-6528/ab9af2
Abstract
Core-shell FexOy@C nanoparticles (NPs) modified with Ag were studied with x-ray diffraction, transmission electron microscopy, energy dispersive elemental mapping, Mossbauer spectroscopy, static magnetic measurements, and optical magnetic circular dichroism (MCD). FexOy@C NPs synthesized by the pyrolysis process of the mixture of Fe(NO3)(3)center dot 9H(2)O with oleylamine and oleic acid were added to a heated mixture of oleylamine and AgNO(3)in different concentrations. The final product was a mixture of iron oxide crystalline NPs in an amorphous carbon shell and Ag crystalline NPs. The iron oxide NPs were presented by two magnetic phases with extremely close crystal structures: Fe(3)O(4)and gamma-Fe2O3. Ag is shown to form crystalline NPs located very close to the iron oxide NPs. An assumption is made about the formation of hybrid FexOy@C-Ag NPs. Correlations were obtained between the Ag concentration in the fabricated samples, their magnetic properties and the MCD spectrum shape. Introducing Ag led to a approximately linear decrease of the NPs saturation magnetization depending upon the Ag concentration, it also resulted into the MCD spectrum shift to the lower light wave energies. MCD was also studied for the Fe3O4@C NPs synthesized earlier with the same one-step process using different heat treatment temperatures, and MCD spectra were compared for two series of NPs. A possible contribution of the surface plasmon excitation in Ag NPs to the MCD spectrum of the FexOy@C-Ag NPs is discussed.Keywords
Funding Information
- Ministry of Science and Higher Education of the Russian Federation (within the State assignment FSRC «Crystallography)
- Russian Foundation for Basic Research (19-52-52002)
- Ministry of Science and Technology (106-2112-M-153-001-MY3)
This publication has 43 references indexed in Scilit:
- Magnetoplasmonics: Combining Magnetic and Plasmonic FunctionalitiesAdvanced Optical Materials, 2013
- Multifunctional Fe3O4@C@Ag hybrid nanoparticles as dual modal imaging probes and near-infrared light-responsive drug delivery platformBiomaterials, 2013
- Magneto-optic studies of magnetic oxidesJournal of Magnetism and Magnetic Materials, 2012
- Silver-coated magnetite–carbon core–shell microspheres as substrate-enhanced SERS probes for detection of trace persistent organic pollutantsNanoscale, 2012
- Exchange bias behavior of monodisperse Fe3O4/γ-Fe2O3 core/shell nanoparticlesCurrent Applied Physics, 2011
- Synthesis and characterization of Fe3O4@C@Ag nanocomposites and their antibacterial performanceApplied Surface Science, 2011
- Vacancy ordering and electronic structure of γ-Fe2O3(maghemite): a theoretical investigationJournal of Physics: Condensed Matter, 2010
- The study of novel Fe3O4@γ-Fe2O3 core/shell nanomaterials with improved propertiesJournal of Magnetism and Magnetic Materials, 2008
- Magneto-optical study of the Verwey transition in magnetiteJournal of Magnetism and Magnetic Materials, 2007
- Microwave hydrothermal preparation of submicron-sized spherical magnetite (Fe3O4) powdersMaterials Letters, 2002