Zirconium titanate from sol-gel synthesis: Thermal decomposition and quantitative phase analysis

Oxides precursors ZrxTi1-xO2 (x = 0.22, 0.39, and 0.60) were prepared by a hydrolytic sol-gel process. The amorphous mixed oxides are homogeneous as deduced from electron microscopy and XPS studies. The crystallization of these amorphous oxides was studied by TGA-DTA and thermodiffractometry. Quantitative analysis of the crystalline phases, obtained at 1000 degrees C, was carried out by the Rietveld method. The samples are mixtures of TiO2, Zr5Ti7O24, and ZrO2 oxides, and the stoichiometry of the stable zirconium titanate phase was found to be Zr5Ti7O24 and not ZrTiO4 (=Zr6Ti6O24). In this work, the power of Rietveld refinements to determine phase ratios of very related land thus very overlapped) phases is shown. (C) 1998 Academic Press.