THE INFLUENCE OF ANIONS ON THE PRODUCTS OF BATIO3 UNDER HYDROTHERMAL CONDITIONS

Tetragonal BaTiO3 has been prepared from a reactive titanium source, t etrabutyl titanate, with barium acetate in alkaline aqueous solution a t temperatures as low as 200-240 degrees C. Various methods, such as X -ray diffraction, differential scanning calorimetry and scanning elect ron microscopy have been used to investigate the effects of alkalinity , an io ns, reactivity of the titanium source and degrees of fill, on the particle sizes and morphologies of BaTiO3 generated hydrothermally . The most appropriate KOH concentration is about 1.0 mol l(-1) in whi ch BaTiO3 is the stablest phase in the BaO-TiO2 system. Compared with chloride and nitrate ions, the acetate ion accelerates the formation o f large-grained particles of BaTiO3 more prominently. A more reactive titanium source and a higher fill can promote the formation of tetrago nal BaTiO3.