Influence of cobalt ferrite content on the structure and magnetic properties of (CoFe2O4)X (SiO2-PVA)100-X nanocomposites

(CoFe2O4)X(SiO2-PVA)100-X (X = 5, 25, 50, 75 and 95%) nanocomposites were prepared via sol-gel route and annealed at 700 and 1100 °C. The influence of CoFe2O4 content on the structure, morphology and magnetic properties of nanocomposites was studied. X-ray diffraction patterns, Mössbauer and Fourier transform infrared spectra revealed the formation of CoFe2O4 as unique magnetic phase. The crystallinity degree increases with the CoFe2O4 content and the annealing temperature. Transmission electron microscopy images revealed the spherical shape of the obtained nanocomposites. Mössbauer spectra exhibit typical magnetic sextets, allowing the calculation of the cations distribution among tetrahedral and octahedral sites and the stoichiometry of CoFe2O4. A strong correlation between the particle morphology and the magnetic properties of nanocomposites was found. The highest saturation magnetization was identified for (CoFe2O4)95(SiO2-PVA)5 nanocomposite.