Synthesis of high tetragonality nanoparticle BaTiO3

New preparation methods for barium titanate powders that can be used for more compact/superior multilayer ceramic capacitors, embedded capacitors, and high capacitance plastic composite materials in microelectronics are described. The methods involve dissolution and precipitation of barium and titanium compounds followed by crystallization at near ambient condition. The particle morphology, tetragonality, and the corresponding dielectric constants are shown to be different for different preparation methods. The mean particle sizes are less than 100nm and smaller for lower dielectric constant of the solvent medium and higher refluxing temperature. The tetragonality is high for the particles synthesized under totally water-free conditions at 180^oC followed by calcination at 600^oC. The dielectric constants of particles prepared under water-based ambient conditions were 490 and 900 after dehydroxylation treatment by N-methyl pyrrolidone.