PREPARATION AND CHARACTERISATION OF COBALT FERRITE BY THE POLYMERISED COMPLEX METHOD

Magnetic nanoparticles of Co-ferrite were prepared by the polymerised complex method. Heating in a vacuum a precursor solution containing citric acid (CA), ethylene glycol (EG) and cobalt and iron salts with a molar ratio of Co/Fe/CA/EG = 1/2/9/22.5 at 130 C produced a brownish transparent polymeric...

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Bibliographic Details
Published in:Materials letters 2005-01, Vol.59 (8/9), p.1056-1060
Main Authors: Montemayor, S M, Garcia-Cerda, L A, Torres-Lubian, J R
Format: Article
Language:English
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Summary:Magnetic nanoparticles of Co-ferrite were prepared by the polymerised complex method. Heating in a vacuum a precursor solution containing citric acid (CA), ethylene glycol (EG) and cobalt and iron salts with a molar ratio of Co/Fe/CA/EG = 1/2/9/22.5 at 130 C produced a brownish transparent polymeric gel, which was characterised by IR and NMR spectroscopy. The results of both techniques suggest two types of reactions: the formation of metal-CA complexes and successive esterification reactions between CA and EG. The organic fraction was removed by controlled thermal treatments (200-800 C) whereby the bimetallic oxide was formed. The powders obtained were characterised by XRD, vibrational sample magnetometry (VSM) and TEM. XRD analysis showed the presence of CoFe2O4 at 400 C. The saturation magnetisation values of the samples increased as a function of calcination temperature and reached a maximum of 79.8 emu/g at 800 C. The TEM images showed spherical nanoparticles with sizes between 20 and 40 nm. 18 refs.
ISSN:0167-577X