Powder characterization and electrical properties of BaTiO3 produced by several powder synthesis methods

BaTiO3 powder, with an average particle diameter of about 170 nm, was fabricated by three synthesis methods (solid state, hydrothermal and co-precipitation), and the variation in properties of the sintered specimens depended on the particle size distribution and shape of the synthesized powder. The electrical properties of the synthesized BaTiO3 were investigated in terms of crystallite size and tetragonality, based on the powder characteristics. Crystallite sizes of the specimens calculated by Debye- Scherrer equation were 31.2 nm, 31.5 nm, and 33.6 nm for the solid state, hydrothermal, and co-precipitation methods, respectively. The tetragonalities (c/a ratio) obtained from the Rietveld refinement method increased from 1.0064 to 1.0075, and to 1.0079 with increasing crystallite size. The high tetragonality causing amplification of the dipole moment enhanced the dielectric constant, and the dielectric constant for the specimen produced by co-precipitation method had the highest value of 5813, due to its highest value of the tetragonality.