Enhancement of the magnetic and dielectric properties of cobalt nanoferrite/polymethyl methacrylate composites

Abstract

Different concentrations of Co-nanoferrite/polymethyl methacrylate (PMMA) composites were prepared. The effect of Co-nanoferrite concentration (x) on the structure, magnetic and dielectric properties of PMMA has been studied. X-ray and TEM measurements revealed the single phase of Co-ferrite of crystallite size 11 nm. FTIR spectra showed the characteristic peaks of PMMA and a shift in the main peak at high Co-nanoferrite concentrations which was explained in terms of its particle size. Magnetic hysteresis curves show the increase of magnetization of the composite with increasing concentration. It was found that both the dielectric constant (ε′) and loss (ε″) decrease rapidly with increasing frequency in the low frequency range and beyond that remain constant. This result was discussed in terms of the response of the different types of polarization to the frequency of the electric field. Moreover, both ε′ and ε″ increased for ferrite concentration 0 ≤ x ≤ 0.8 and then decreased for higher x values. This was explained according to the increased amount of the dispersed ferrite particles within the polymer matrix and the continuous increase in the particles agglomerations of the nanoferrite with increasing concentration.