The characterization of Co-nanoparticles supported on graphene
Autor: | Alexander Moewes, Gap Soo Chang, D. W. Boukhvalov, Adrian Hunt, Young Hee Lee, Ernst Z. Kurmaev, Paul Bazylewski, Andrey I. Kukharenko, Seif O. Cholakh |
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Rok vydání: | 2015 |
Předmět: |
GRAPHENE
Materials science General Chemical Engineering Oxide Analytical chemistry Nanoparticle chemistry.chemical_element FOS: Physical sciences OXIDATION law.invention Metal chemistry.chemical_compound X-ray photoelectron spectroscopy law Oxidation state Physics - Chemical Physics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) NANOPARTICLES COBALT X RAY PHOTOELECTRON SPECTROSCOPY DENSITY FUNCTIONAL THEORY Chemical Physics (physics.chem-ph) Condensed Matter - Materials Science Condensed Matter - Mesoscale and Nanoscale Physics Graphene PROTECTIVE OXIDE LAYERS COBALT COMPOUNDS Materials Science (cond-mat.mtrl-sci) General Chemistry Computational Physics (physics.comp-ph) OXIDATION STATE COBALT OXIDES chemistry visual_art NANOMAGNETICS CO NANOPARTICLES MAGNETIC PROPERTIES OF CO visual_art.visual_art_medium Density functional theory Physics - Computational Physics Cobalt |
Zdroj: | RSC Adv. RSC Advances |
DOI: | 10.48550/arxiv.1509.00575 |
Popis: | The results of density functional theory calculations and measurements using X-ray photoelectron spectroscopy of Co-nanoparticles dispersed on graphene/Cu are presented. It is found that for low cobalt thickness (0.02 nm - 0.06 nm) the Co forms islands distributed non-homogeneously which are strongly oxidized under exposure to air to form cobalt oxides. At greater thicknesses up to 2 nm the upper Co-layers are similarly oxidized whereas the lower layers contacting the graphene remain metallic. The measurements indicate a Co2+ oxidation state with no evidence of a 3+ state appearing at any Co thickness, consistent with CoO and Co[OH]2. The results show that thicker Co (2nm) coverage induces the formation of a protective oxide layer while providing the magnetic properties of Co nanoparticles. Comment: 20 pages, 8 figures, accepted to RSC Advances. arXiv admin note: text overlap with arXiv:1411.3611 |
Databáze: | OpenAIRE |
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