Question

Formation mechanism of barium titanate by solid-state reactions kolthoum i. Othman1, ahmed a. Hassan1, omar a. A. Abdelal1, ezzat s. Elshazly1, m. El-sayed ali1, s. M. El-raghy2, s. El-houte1

Answer 1

The solid state reactions of BaTiO3 formation from a mechanically activated BaCO3-TiO2 powder mixture have been investigated. Thermogravimetric TGA, thermomechanical TMA, scanning electron microscopy SEM, X-ray diffraction XRD and reactions thermodynamic analyses have been used in the present study. The results of these analyses showed that, the formation of BaTiO3 proceeds through a direct reaction between BaCO3 and TiO2, not through the decomposition of BaCO3 to BaO neither through the formation of Ba2TiO4 intermediate phase. The agglomerated nature of the milled powder, its rearrangement during the course of the reaction, the particle size of BaCO3 and TiO2 and the effect of the evolved CO2 gas in the reaction zone are the major factors affecting the mechanism of reaction between BaCO3 and TiO2.

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