The influence of silica matrix on the crystal structure and high frequency performance of cobalt nanoparticles

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

OSTI ID:21421545

Gongying, Liang; Qianjin, Sun; Caihua, Yang ^[1]

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1. MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, Xi'an 710049 (China)

Cobalt-SiO{sub 2} nanocomposites were successfully synthesized by chemical precipitation combined H{sub 2} reduction method. The influence of SiO{sub 2} matrix on the crystal structure and high frequency magnetic properties of cobalt nanoparticles was investigated. Amorphous SiO{sub 2} layer, which is adhered to Co particle surface through Si-O-Co bonds, inhibits the growth of the nanoparticles and stabilizes the face-centered-cubic (FCC) structured Co. The FCC-cobalt/SiO{sub 2} nanocomposites exhibit soft magnetic behavior with saturation magnetization (M{sub s}) about 125 emu/g and coercivity (H{sub c}) smaller than 100 Oe. The permeability spectra of Co/SiO{sub 2} nanocomposites depend on the SiO{sub 2} contents. When the SiO{sub 2} content is greater than 8 wt%, the permeability spectra demonstrate notable high frequency characteristic, in which the real part {mu}' of the permeability is almost independent of frequency and the imaginary part {mu}'' remains extremely low in high frequency range. - Graphical abstract: Co NPs are encapsulated by SiO{sub 2} mediated by Si-O-Co bonds. This SiO{sub 2} matrix stabilizes FCC-Co and improves the high-frequency performance of Co NPs.

• OSTI ID: 21421545
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 7; Other Information: DOI: 10.1016/j.jssc.2010.04.031; PII: S0022-4596(10)00178-7; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
COBALT
COERCIVE FORCE
COMPOSITE MATERIALS
FCC LATTICES
HYDROGEN
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETIZATION
NANOSTRUCTURES
PERMEABILITY
PRECIPITATION
REDUCTION
SILICON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
ELEMENTS
MATERIALS
METALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SEPARATION PROCESSES
SILICON COMPOUNDS
TRANSITION ELEMENTS