Abstract

SynthesisOfCobalt FerriteNanoparticlesUsing The Sol-GelMethod

Author(s): R.S.de Biasi, A.B.S.Figueiredo, A.A.R.Fernandes, C.Larica

Nanocrystalline particles of cobalt ferrite (CoFe2O4) were prepared by the sol-gel method using iron nitrate, Fe(NO3)3.9H2O, cobalt nitrate, Co(NO3)2.6H2O, and TEOS, Si(OC2H5)4. The average particle size, determined by X-ray diffraction, was found to depend on the calcination temperature and varied between 13 and 30 nm. By measuring at several temperatures the relative intensity of the Mössbauer spectra due to superparamagnetic particles and to ferrimagnetic particles, we determined the size distribution of the nanoparticles in one of the samples. It was found to be a log-normal distribution with a most probable diameter Dm=6.6nm and a full width at half-height D=0.4nm.