Fe2O3/TiO2 nanoparticles-a complex structural study

We report on the structure and arrangement of particles created in the Fe2O3/TiO2 + SiO2 multilayers. X-ray diffraction and extended X-ray absorption fine structure spectroscopy reveal the presence of crystalline rutile-TiO2 while the iron oxide remains either amorphous or forms very small clusters of Fe2O3. The Fe3 + oxidation state of iron atoms has been confirmed by Mössbauer and X-ray spectroscopy. The degree of the particle ordering has been studied by grazing-incidence small-angle X-ray scattering. It was demonstrated that with increasing temperature partially ordered nanoparticles are created and grow up to a critical temperature when the ordering is destroyed. Both particle sizes and inter-particle distances depend strongly on the thickness of the Ti/Fe containing layer.