Core@shell nanocomposites Fe7C3 / FexOy /C obtained by high pressure-high temperature treatment of ferrocene Fe(C5H5)2
| Autor: | A. O. Baskakov, Igor S. Lyubutin, V. A. Davydov, K. O. Funtov, Yu. A. Nikiforova, L.F. Kulikova, Alexander L. Vasiliev, S. S. Starchikov, V. N. Agafonov, V.A. Zayakhanov, Marianna V. Lyubutina |
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| Přispěvatelé: | GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Iron oxide chemistry.chemical_element Nanoparticle 02 engineering and technology engineering.material 010402 general chemistry 01 natural sciences law.invention Carbide chemistry.chemical_compound law General Materials Science Wüstite Crystallization ComputingMilieux_MISCELLANEOUS Magnetite General Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph] Chemical engineering chemistry engineering Orthorhombic crystal system 0210 nano-technology Carbon |
| Zdroj: | Carbon Carbon, 2021, 178, pp.708-717. ⟨10.1016/j.carbon.2021.03.052⟩ |
| ISSN: | 0008-6223 |
| DOI: | 10.1016/j.carbon.2021.03.052⟩ |
| Popis: | The core@shell nanostructures were obtained in the process of transformation of ferrocene Fe(C5H5)2 at high pressure (HP) of 8 GPa and high temperature (HT) of 900 °C with an isothermal exposure time t varying from 10 to 10000 s. At t > 300 s, the iron carbide o-Fe7C3 nanoparticles with an orthorhombic crystal structure (sp.gr. Pnma) can be created, which are dispersed in highly defective carbon matrix. After opening the high-pressure cell, a series of redox reactions occurs, leading to a formation of iron oxides on the surface of the iron carbide core. When the size of Fe7C3 nanoparticle is less than critical one the nanoparticle is fully oxidized, while in the larger particle an amorphous iron oxide shell is formed. A sequential increase in t initiates crystallization processes both in the iron carbide subsystem and in the carbon subsystem, resulting in the formation of core@shell Fe7C3/FexOy/C structures. Iron oxides with a cubic spinel-type structure (Fe3O4/γ-Fe2O3) appear in the shell. However, under oxygen reduction, part of magnetite can be transformed into wustite FeO. The magnetic properties of magnetite and wustite are radically different, and by varying the thickness of these layers, structures with the desired functional properties can be obtained. |
| Databáze: | OpenAIRE |
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