journal article·2004-05

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

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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.
Source: openaire · Quality: candidate unverified · Source record ↗

Research context

OpenAlex topics: Magnetic Properties and Synthesis of Ferrites · Magneto-Optical Properties and Applications · Iron oxide chemistry and applications

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References (6)

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1. H. Singh Nalwa (Ed.), Handbook of Nanostructured Materials and Nanotechnology, Academic Press, San Diego, 2000.
2. G. Ennas, et al., J. Nanoparticles Res., in press.
3. Tronc · Nuovo Cimento · 1996 · 18D · 16310.1007/BF02458890 ↗
4. E. Murad, et al.,in: G.J. Long (Ed.), Mössbauer Spectroscopy Applied to Inorganic Chemistry, Vol. 2, Plenum, New York, 1987, p. 507.
5. Slonczewski · J. Appl. Phys. · 1959 · 32 · 253S10.1063/1.2000425 ↗
6. Tronc · J. Magn. Magn. Mater. · 2000 · 221 · 6310.1016/S0304-8853(00)00369-3 ↗