Preparation of nanometer-sized barium titanate powders by a sol-precipitation process with surfactants

Nanometer sized barium titanate powders can be obtained by adding surfactants to titanyl acylate precursors in a strong alkaline solution (pH>13). FTIR, TGA, SEM and XRD were used to investigate the effects of the surfactants influence on the morphology of the obtained titanate powders and their sinterability. In a pre-added surfactant process (i.e. surfactant added before precipitation in alkaline solution), a slower rate of hydrolyzation is observed, and the shift rate in the condensation is slower. Less crosslinking of smaller particles is observed. The addition of anionic surfactant (LAS) in general leads to the formation of micelles, which control the nucleation and crystal growth of the titanate powders. This micelle formation results in a smaller particle size (30–90 nm), and a larger surface area of 60.5 m2/g for BaTiO3 powders was obtained. The nanometer-sized barium titanate powders were readily sintered at 1100–1200 °C.