Effect of ZrO₂ on the structure of ZrO₂/TiO₂/SiO₂ nanocomposites fabricated by a template sol–gel method

ZrO₂/TiO₂/SiO₂ (ZrO₂ up to 6.7 mass%) composites with variable oxide ratios that were fabricated by a template sol-gel method were studied. The morphology was described. The structure was analyzed using scanning electron and confocal laser microscopy, small-angle x-ray scattering, and Raman spectroscopy. It was established that the composites were nanostructured micron-sized tubes of ZrO₂/TiO₂/SiO₂. The microtubes were constructed from nanoparticles with the anatase structure and general formula Ti_1-xZr_xO₂ (x = 0-0.05). Changes of Raman spectra were examined as a function of ZrO₂ content in the composites and the annealing temperature. The contribution of optical phonon scattering to the ν8(E_1g) peak position was determined. The ν4(B_1g) peak position and the gyration radius of the nanocrystallites were shown to be related. (authors)