Synthesis of nano-sized barium titanate powders and study on sintering kinetic

Two-step precipitation route was developed to synthesize nano-sized BaTiO3 powders with cubic phase structure at low temperature and under ambient pressure,using TiCl4,Ba(OH)2·8H2O and NH3·H2O as raw materials.During the process,titanium hydroxides gel was obtained firstly and then reacted with barium hydroxide,with ethanol as reaction medium.The influences of reaction temperature,reactant concentration and reaction time on phase composition and particle size were studied,and the as-prepared powders were characterized by XRD and TEM.The results show that well-crystalline BaTiO3 powders with particle size smaller than 20nm can be obtained at temperature lower than 80℃.In addition,using as-prepared powders,the characteristics of sintering kinetic curves of BaTiO3 ceramic were studied by means of a thermal dilatometer.The results confirm that sintering temperature was 1150-1250℃ and the relative density of ceramic sintered at 1250℃ for 2h was about 93% with dielectric constant evaluated 4020 at room temperature.