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Three different Ti-Si oxide structuares,silica supported titania,silica coated titania and intimately mixed silica- titania,containing 10%-40% SiO_2,were made by sol-gel process.The variations of microstructure parameters of nanocrystalline(nc)TiO_2-anatase in the three kirds of binary oxides,including in-plane spacing d,cell constants(a_0,c_0),cell volume V,cell axial ratio c_0/a_0 and crystal grain size,were comparatively investigated by high resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD).It is found that the microstructure parameters vary remarkably with increasing SiO_2 content and annealing temperature.Different structured Ti-Si binary oxides lead to different variation tendencies of microstructure parameters.The more SiO_2 the binary oxide contains,the more lattice defects of nc TiO_2-anatase appear;diffusion or migration of Si cations could be an important influential factor in the variations of microstructure.The grain size of nc TiO_2 in the three kinds of binary oxides not only depends on SiO_2 content and annealing temperature but also on the degree of lattice microstrain and distortion of nc TiO_2-anatase.Both grain size and phase transformation of nc TiO_2-anatase are effectively inhibited with increasing SiP_2 content.
Three different Ti-Si oxide struuares, silica supported titania, silica coated titania and intimately mixed silica- titania, containing 10% -40% SiO 2, were made by sol-gel process. The variations of microstructure parameters of nanocrystalline (nc) TiO_2- Anasease in the three kirds of binary oxides, including in-plane spacing d, cell constants (a_0, c_0), cell volume V, cell axial ratio c_0 / a_0 and crystal grain size, were analyzedly investigated by high resolution transmission electron microscopy (HRTEM ) and X-ray diffraction (XRD) .It is found that the microstructure parameters vary remarkably with increasing SiO 2 content and annealing temperature. Differently structured Ti-Si binary oxides lead to different variation tendencies of microstructure parameters. The more SiO 2 the binary oxide contains , the more lattice defects of nc TiO_2-anatase appear; diffusion or migration of Si cations could be an important influential factor in the variations of microstructure. grain size of nc TiO_2 in the three kinds of binary oxides not only on SiO 2 content and annealing temperature but also on the degree of lattice microstrain and distortion of nc TiO_2 -anatase.Both grain size and phase transformation of nc TiO_2-anatase are effectively inhibited with increasing SiP_2 content.