Resumo

LOPEZ, J. et al. Caracterización de nanopartículas magnéticas de CoFe₂O₄ y CoZnFe₂O₄ preparadas por el método de coprecipitación química. Rev. mex. fis. [online]. 2012, vol.58, n.4, pp.293-300. ISSN 0035-001X.

Magnetic cobalt ferrite nanoparticles of CoFe₂O₄ and CoZnFe₂O₄ were prepared by co-precipitation technique from aqueous salt solutions of Co (II), ZnSO₄ and Fe (III), in an alkaline medium. CoFe₂C₄ powder samples were structurally characterized by X-ray diffraction, showing the presence of the most intense peak at 2θ= 413928° (Co Kαl) corresponding to the (311) crystallographic orientation of the CoFe₂C₄ spinel phase. The mean size of the crystallite of CoFe₂C₄ y CoZnFe₂C₄ nanoparticles determined from the full-width at half maximum (FWHM) of the strongest reflection of the (311) peak by using the Scherrer approximation was calculated to be 11.4 and 7.0 (± 0.2) nm, respectively. Transmission Electron Microscopy (TEM) studies permitted determining nanoparticle size of CoZnFe₂C₄. Fourier Transform Infrared Spectroscopy was used to confirm the formation of Fe-O bonds, allowing identifying the presence of ferrite spinel structure. Magnetic properties were investigated with the aid of a vibrating sample magnetometer (VSM) at room temperature Herein, the sample showed superparamagnetic behavior, determined by the hysteresis loop Finally, due to the hysteresis loop of the CoZnFe₂C₄ is very small, our magnetic nanoparticles can be considered as a soft magnetic material. These magnetic nanoparticles have interesting technological applications in biomedicine given their biocompatibility, in nanotechnology, and in ferrofluid preparation.

Palavras-chave : Coprecipitation; cobalt - zinc ferrites; nanoparticles; spinel structure.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )