CoFe2O4 nanoparticles prepared by the mechanochemical method

Cobalt ferrite nanoparticles have been prepared by the combination of chemi cal precipitation, mechanical alloying and subsequent heat treatment. Sodiu m chloride was added before milling in order to avoid agglomeration. From X RD measurements it was found that the cobalt ferrite phase could form direc tly during mechanical milling of the precipitated hydroxide/oxidhydroxide p recursor. Long-term milling caused contamination and growth in particle siz e. In order to reduce these two undesirable effects, a revised processing r oute, milling at a lower speed for a relatively shorter time and further he at treatment, was adopted. CoFe2O4 nanoparticles were obtained after a simp le washing process with deionised water. TEM measurements showed that the n anoparticles had a fairly uniform structure and a mean particle size of app roximately 10 nm. Anisotropic nanoparticles were obtained after magnetic an nealing at 300 degrees C. (C) 2000 Elsevier Science S.A. All rights reserve d.