Caracterización de nanopartículas magnéticas de CoFe$_{2}$o$_{4}$ y CoZnFe$_{2}$O$_{4}$ preparadas por el método de coprecipitación química

Abstract

Magnetic cobalt ferrite nanoparticles of CoFe$_{2}$O$_{4}$ and CoZnFe$_{2}$O$_{4}$ were prepared by co-precipitation technique from aqueous salt solutions of Co (II), ZnSO$_{4}$ and Fe (III), in an alkaline medium. CoFe$_{2}$O$_{4}$ powder samples were structurally characterized by X-ray diffraction, showing the presence of the most intense peak at 2$\theta $ = 413928$^{\circ}$ (Co K$\alpha $1) corresponding to the (311) crystallographic orientation of the CoFe$_{2}$O$_{4 }$spinel phase. The mean size of the crystallite of CoFe$_{2}$O$_{4}$ y CoZnFe$_{2}$O$_{4 }$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 ($\pm $~0.2) nm, respectively. Transmission Electron Microscopy (TEM) studies permitted determining nanoparticle size of CoZnFe$_{2}$O$_{4}$. Fourier Transform Infrared Spectroscopy was used to confirm the formation of Fe--O bonds, allowing identifying the presence of ferrite spinel structure. Magnetic properties were investigated with the aid of a vibrating sample magnetometer (VSM) at room temperature Herein, the sample showed superparamagnetic behavior, determined by the hysteresis loop Finally, due to the hysteresis loop of the CoZnFe$_{2}$O$_{4 }$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.