Grain growth kinetics of barium titanate synthesized using conventional solid state reaction route

BaTiO3 was synthesized by solid state reaction between BaCO3 and TiO2 at 1150 degrees C. XRD analysis of the powder confirmed the formation of phase pure tetragonal powder. The particle size of BaTiO3 powder was of the order of 0.7 mu m. In order to study grain growth kinetics of BaTiO3, isothermal sintering was carried out at 1200, 1250 and 1300 degrees C for the time durations of 2, 4 and 6 h at each of these temperatures. Average grain size increased from 0.4 mu m to 1.1 mu m on increasing time and temperature of sintering. Corresponding to the temperatures of 1200, 1250 and 1300 degrees C, grain growth exponents obtained using phenomenological kinetic grain growth equation decreased in the order of 9.77, 4.61 and 3.08 indicating rapid coarsening with increased temperature. Grain growth exponents as high as 4.61 and 9.77 can be regarded as the result of mixed diffusion while grain growth exponent of 3.08 can be the result of pore controlled lattice diffusion. Activation energies calculated in correspondence of grain growth exponents of 9.77, 4.61 and 3.08 were 1307 +/- 65, 567 +/- 30 and 439 +/- 20 kJ/mol respectively. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved