On the formation of BaTiO3 from BaCO3 and TiO2 by microwave and conventional heating

formation of BaTiO3 from solid-state BaCO3 and TiO2 was investigated by microwave processing and by conventional heating. In both cases, moderate heating and cooling rates of 10 K/min were used. X-ray diffraction analysis revealed no significant difference in detected phases as well as in the reaction paths for both processing routes. In particular, the intermediate compound Ba2TiO4 was also found in samples produced by microwave heating. Both of the known modifications of Ba2TiO4 were detected and are with noticeable amounts of the orthorhombic phase and traces of the monoclinic one. In these two phases, at least the orthorhombic modification is not stable in humid air and decomposes slowly to BaTiO3, and BaCO3. (C) 2004 Elsevier B.V. All rights reserved.