Small-Angle X-Ray Scattering Study And Doping Effect Of The Nano-Titania

Small-angle X-ray scattering (SAXS) is the technique of choice for probing structure features that occur on length scales between approximately Inm and 100nm. The only requirement for SAXS is the presence of inhomogeneities in electron density. There is an increasing interest on the SAXS study of the oxide nanoparticles and porous materials in recent years.The pure nano-TiO2 and doped-TiO2 are prepared by sol-gel process. The samples were investigated by synchrotron Small-Angle X-Ray Scattering, DTA and XRD. The size and microstructure were characterized. The phase transition behavior of sample was analyzed by using SAXS fractal theory. The relationship between Porod's law and specific surface was found first time. The average particle size increased with the annealing temperature increasing. When the temperature increased high enough, the anatase changed into rutile. A little Nb2O5or cerium doped into sample can change phase-transition temperature and influence the growth of particle. SAXS indicates that all anatase follow Porod's law but not show any fractal structure. Other samples gave a positive deviation from Porod's law.