Growth of nano-α-Fe₂O₃ in a titania matrix by the sol-gel route

Abstract

Nano-α-Fe₂O₃ in a titania matrix was prepared by the sol-gel route. The nanocomposites containing various sizes of α-Fe₂O₃ were precipitated by the heat treatment of the dried gel in a temperature range 100-1200°C. Differential thermal analysis of the TiO₂-Fe₂O₃ system showed peaks at 325, 390 and 730°C. The formation of anatase as well as the rutile phase of TiO₂ and the growth of α-Fe₂O₃ were predicted from the above peak analysis. These results were in agreement with the X-ray diffraction studies. The sizes of the nanoparticles were analysed by transmission electron microscopic studies. The Mossbauer spectra of TiO₂-Fe₂O₃ nanocomposites showed paramagnetic and superparamagnetic doublets for all the specimens containing nanoparticles of α-Fe₂O₃. The electron paramagnetic resonance study indicated the presence of a paramagnetic phase in the nanocomposite samples.