Characterization of the dispersion process for NiFe2O4 nanocrystals in a silica matrix with infrared spectroscopy and electron paramagnetic resonance

Li Guang-She, Li Li-Ping, R. L. Smith, H. Inomata

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54 Citations (Scopus)


The structural development of the NiFe2O4 nanocrystals dispersed in a silica matrix was followed by IR and EPR spectroscopies of the dried gel 10NiO-10Fe2O3-90SiO2 after heat treatment. The dried gel obtained at 200°C was amorphous, in which Fe3+ and Ni2+ ions were distributed in the pores of silica matrix. When the dried gel was heat treated at 400°C, NiFe2 O4 clusters were partially formed, showing an enhanced interaction with the silica matrix. NiFe2O4 clusters were completely formed in silica matrix when the heat treatment was increased to 600°C, at which the interactions between the clusters and silica matrix reached a maximum. The formation reaction of NiFe2O4 clusters was accompanied by a rearrangement of the silica matrix network. Further increase of the heat treatment temperature to 800°c led to superparamagnetic single domain NiFe2O4 nanocrystals (ca. 4 nm) dispersed in the silica matrix with the elimination of the interactions between magnetic nanocrystals and silica matrix.

Original languageEnglish
Pages (from-to)87-93
Number of pages7
JournalJournal of Molecular Structure
Issue number1-3
Publication statusPublished - 2001 Jan 29


  • Electron paramagnetic resonance
  • Infrared spectroscopy
  • Nickel ferrite

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry
  • Inorganic Chemistry

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