Carbon-encapsulated cobalt nanoparticles: synthesis, properties, and magnetic particle hyperthermia efficiency
Autor: | Catherine Dendrinou-Samara, A. Kotoulas, J. Arvanitidis, G. Vourlias, Mavroeidis Angelakeris, Orestis Kalogirou, C. Sarafidis, Th. Kehagias |
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Rok vydání: | 2017 |
Předmět: |
Materials science
Nanoparticle chemistry.chemical_element Bioengineering 02 engineering and technology Magnetic particle inspection 010402 general chemistry 01 natural sciences symbols.namesake General Materials Science Compounds of carbon High-resolution transmission electron microscopy chemistry.chemical_classification General Chemistry Coercivity 021001 nanoscience & nanotechnology Condensed Matter Physics Atomic and Molecular Physics and Optics 0104 chemical sciences chemistry Chemical engineering Modeling and Simulation symbols 0210 nano-technology Raman spectroscopy Cobalt Powder diffraction |
Zdroj: | Journal of Nanoparticle Research. 19 |
ISSN: | 1572-896X 1388-0764 |
DOI: | 10.1007/s11051-017-4099-9 |
Popis: | A facile and low-cost method for structuring carbon-encapsulated cobalt nanoparticles (Co@C) is presented. Three samples were solvothermally prepared in one step at 220 °C and one in two steps at 200 °C. Three different polyols such as propylene glycol, triethylene glycol, and tetraethylene glycol were used as carbon sources, solvents, and reducing agents. The samples were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. Concerning the crystal structure of the particles, a mixture of hcp/fcc Co phases was obtained in three of the samples, independently of the polyol used. The coexistence of cubic and hexagonal phases was revealed both from XRD and high-resolution TEM (HRTEM). The formation of the cubic fcc structure, despite the relatively low reaction temperature, is attributed to the role of the interface between carbon coating and metallic core. The presence of carbon coating was demonstrated by Raman spectrometry, exhibiting the characteristic D and G graphitic bands, and by HRTEM observations. All samples showed ferromagnetic behavior with saturation magnetization up to 158 emu/g and coercivity up to 206 Oe. From the magnetic particle hyperthermia measurements recorded at a frequency of 765 kHz, a maximum SLP value of 241 W/g was obtained. |
Databáze: | OpenAIRE |
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