Papers by Author: Sang Man Koo

Abstract: Ethanol-based antimony-tin oxide (ATO) and vanadium-doped ATO (V-ATO) nano-sol solutions were prepared in H2O containing tetramethylammonium hydroxide by peptizing their coagulated precipitates which were synthesized by hydrothermal reaction at 170°C in an autoclave. Also, the ATO and V-ATO films were formed by spin coating to be investigated with dopants (V, Sb) and solid content on their conductivity and transparency.

Abstract: We have investigated a novel synthesis for highly spherical and ultrafine barium titanate (BaTiO3) powders using a peptized titania (TiO2) nano-sol as a precursor. The obtained TiO2 nano-sol had the size less than 10 nm, which could be easily converted to BaTiO3 under 100 °C. The size of the resulting BaTiO3 powder could be controlled from 42 to 167 nm by lowering the solution concentration from 1.00 M to 0.15 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 as-prepared BaTiO3 with smaller size had higher tetragonality and less intra-granular pores after annealing.