학술논문
Cobalt-containing core-shell nanoparticles on the surface of poly(tetrafluoroethylene) microgranules.
Document Type
Article
Author
Source
Subject
*COBALT
*NANOPARTICLES
*TRANSITION metals
*X-ray spectroscopy
*MAGNETIC properties
*LIGHT elements
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Language
ISSN
0020-1685
Abstract
Cobalt-containing nanoparticles have been prepared via thermal decomposition of cobalt acetate on the surface of poly(tetrafluoroethylene) (PTFE) microgranules forming a fluidized bed over the surface of hot mineral oil. Using transmission electron microscopy, the average size of the cobalt-containing nanoparticles has been determined to be 3.6 nm. The composition and structure of the nanoparticles have been determined by x-ray diffraction, extended x-ray absorption fine structure spectroscopy, and electron paramagnetic resonance, and the magnetic properties of the synthesized nanomaterial have been studied. The results indicate that the nanoparticles have a core-shell structure, with a metallic cobalt core (≃10 vol%) and a shell consisting of three phases: Co3O4 (≃80%) and small amounts of CoO and CoF2 (≃10%). The fluoride phase results from the interaction of the nanoparticles with surface fluorine atoms of the PTFE microgranules. [ABSTRACT FROM AUTHOR]