Raman study of nanoparticle-template interaction in a CoFe2O4/SiO2-based nanocomposite prepared by sol-gel method

Cobalt-ferrite nanocomposites consisting of magnetic nanoparticles dispersed in silica matrix were prepared by a sol-gel technique. Samples with different nanoparticle concentration, dried at room temperature and at 900 deg C were investigated using Raman spectroscopy. Composite samples dried at room temperature show a competition among Si-O-Si and Si-OH bonds. Concentrated composite samples, dried at room temperature, present strong interaction between CoFe2O4 nanoparticles and the silica matrix. However, for samples dried at 900 deg C, these interactions occur in the low nanoparticles concentration