Novel Synthesis of Ultrafine Barium Titanate Powders Using Peptized Titania Nano-sol

초록

Barium titanate (BaTiO3) is a widely used material for electronic devices such as multi-layer ceramic capacitors, positive temperature coefficient resistors and electro-optic devices. Especially the required characteristics of the BaTiO3 for multi-layer ceramic capacitors with thinner dielectric layers are small particle size with narrow distribution and high tetragonality with fewer defects such as intragranular pores. We have investigated a novel and economical synthesis for highly spherical and ultrafine BaTiO3 powders using peptized titania nano-sol as a precursor. The obtained titania nano-sol had the size less than 10 nm, which was easily converted to BaTiO3 under 100 ℃. The size of the resulting BaTiO3 powder was controlled from 42 to 132 nm by lowering the solution concentration from 1.00 M to 0.25 M. BET analysis indicated that the as-prepared BaTiO3 powders had some porosity which was increased with the particle size. It was also found that the BaTiO3 with smaller size had higher tetragonality and less intragranular pores after calcination.