Barium titanate derived from mechanochemically activated powders

A high-energy ball milling process was applied to a mixture with equal molar ratio of BaCO3 and TiO2. X-ray diffraction data indicated that there was no reaction happening during. the milling process although the particle size was greatly reduced. The effect of post-annealing on the phase formation and grain growth of BaTiO3 was investigated by thermal analysis (DTA/TGA). X-ray diffraction (XRD) and scanning electron microscopy (SEM). No reaction was observed in the sample annealed at 600degreesC. Ba2TiO4 was found as the mixture annealed at 700degreesC. An 800degreesC-annealing led to single phase BaTiO3 with a cubic structure. The temperature at which BaTiO3 phase was derived is lower than required by the solid-state reaction process, which could be attributed to the refined grains/particles of the mixture as a result of high-energy ball milling. Tetragonal structured BaTiO3 was formed at 1150degreesC to,,ether with a sharp increase in,grain size. (C) 2002 Elsevier Science B.V. All rights reserved.