Magnetic properties of nanocrystalline CoFe2O4 dispersed in amorphous silica

Francesco Congiu, Giorgio Concas, Guido Ennas, Andrea Falqui*, Dino Fiorani, Giaime Marongiu, Sergio Marras, Giorgio Spano, Alberto M. Testa

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

23 Scopus citations

Abstract

Almost spherical CoFe2O4 nanocrystals with a narrow size distribution centered around 2.5(5)nm, uniformly dispersed in an amorphous SiO2 matrix have been prepared by high energy ball milling followed by thermal treatment at 900°C. Mössbauer spectra show the presence of CoFe2O4 nanoparticles in the superparamagnetic state at 293K and mainly in the blocked state at 77K. This is confirmed by ZFC/FC measurements giving evidence of a distribution of blocking temperatures, centered at 50K.

Original languageEnglish (US)
Pages (from-to)1561-1562
Number of pages2
JournalJournal of Magnetism and Magnetic Materials
Volume272-276
DOIs
StatePublished - May 1 2004
EventProceedings of the International Conference on Magnetism - Rome, Italy
Duration: Jul 27 2003Aug 1 2003

Keywords

  • Cobalt ferrite
  • Nanocomposite
  • Superparamagnetism

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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