Thermal behaviour of a TiO2-ZrO2 microcomposite prepared by chemical coating

A microcomposite powder in the system TiO2-ZrO2 as a precursor of zirconium titanate (ZT) materials has been studied by thermal methods (DTA-TG) and X-ray diffraction (XRD). The microcomposite powder has been prepared by chemical processing of crystalline TiO2 (rutile, 10 mass% anatase), as inner core, coated with in situ precipitated amorphous hydrated zirconia gel, as outer core. The morphology and chemical composition of the resultant powders has been examined by SEM-EDX (Scanning electron microscopy-energy dispersive X-ray spectroscopy). Thermal behaviour of the microcomposite powder was reported, showing the dehydration and dehydroxylation of the zirconia gel, the crystallization into metastable cubic/tetragonal zirconia at temperatures 400-470degreesC, and the feasibility of preparing ZT powder materials by progressive reaction of TiO2 and ZrO2 at higher temperatures (1400degreesC).