Abstract
Calcium titanate crystallization has been observed following the hydrothermal reaction of titanium dioxide (TiO 2) and calcium in alkaline solution at 250 °C, using time-resolved in situ energy-dispersive diffraction. The nature of the calcium source used was found to influence the type of calcium titanate formed; CaTiO 3 was produced when calcium carbonate was used and Ca(TiO 2) 2(OH) 2 was produced when the calcium aluminosilicate, Ca 3Al 2(SiO 4)(OH) 8 was used. Temperature had a significant effect on the formation of CaTiO 3, as observed in the range 200-250 °C. A less-significant effect was apparent for the formation of Ca(TiO 2) 2(OH) 2 in the same range. Kinetic analysis of the crystallization of both calcium titanates was performed in the region 200-250 °C by applying the Avrami-Erofe'ev equation to the growth data. Activation energies of 89 and 58 kJ mol -1 were returned for the formation of CaTiO 3 and Ca(TiO 2) 2(OH) 2, respectively.
Original language | English |
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Pages (from-to) | 2207-2213 |
Number of pages | 7 |
Journal | Crystal Growth and Design |
Volume | 9 |
Issue number | 5 |
DOIs | |
Publication status | Published - 6 May 2009 |