Ceramics-Silikáty 38, (3) 163 - 165 (1994) |
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STUNY OF SYNTHESIS AND MORPHOLOGY OF BaTiO₃ CRYSTALS PREPARED FROM MOLTEN SALTS
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Lubyová Želmíra, Daněk Vladimír |
Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 842 36 Bratislava, Slovakia
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The synthesis of barium-titanium mixed oxide, BaTiO₃, from the mixture of barium sulphate, sodium carbonate and titanium oxide in the medium of the molten alkali metal chlorides was realized at the temperatures of 700-900 °C and reaction times of 1-30 min. The conversion degree increases both with temperature and time of heating and in the presence of flux attains at 900 °C almost 100%. The synthetized powders contained BaTiO₃ crystals of two different morphology. The equiaxed BaTiO₃ crystals originate most probably by disintegration of the primarily formed rod-like crystals. According to the X-ray diffraction analysis all prepared powders contain only the tetragonal modification of BaTiO₃. The activation energy of the BaTiO₃ formation was found to be ΔE(BaTiO₃) = 124.6 kJ/mol. |
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