Rietveld refinement, micro-structural, optical and thermal parameters of zirconium titanate composites

Pure titania and zirconium titanate composites have been synthesized using sol-gel technique and annealed at 650, 875 and 1100 degrees C for 4 h. Acetylacetone was used to control the rate of hydrolysis of precursors. The Rietveld refinement, micro-structural, optical and thermal parameters of prepared composites was investigated. Effect of annealing and concentration of Zr and Ti in composites on their crystal structure, morphology, PL emission wavelength and band gap have been studied. X-ray diffraction and Rietveld analysis exhibit that all prepared samples of composites have orthorhombic single phase of zirconium titanate with space group pbcn. The lower values of profile parameters such as R-p, R-wp, R-B, R-F, chi(2) indicated that the calculated diffraction pattern is in fair agreement with observed pattern. The increase in zirconia concentration decreases the degree of crystallization of ZrTiO4. The photoluminescence spectra show the blue shifting of emission peak at 420 nm as the zirconia concentration increases. The optical band gap of zirconium titanate composites also blue shifted (3.24-3.64 eV) with decrease in crystallite size of composites.