Preparation Of Nano Barium Titanate Powder And Study On Its Performance

BaTiO₃ electronic ceramics is the basic material of dielectric and semiconductor ceramics, which was widely used in martial and demotic electronic machine. With the development of information technology, the characters of BaTiO₃ electronic ceramic were demanded more and more advanced, the performance depends largely on the quality of raw material powder, but the traditional techniques of powder preparation have been not reached the performance requirement, so it is the studying emphases and hotspot that adopting advanced techniques to prepare fine BaTiO₃ powder. This article summarized the preparation methods of BaTiO₃ powder and its futurity, and improved the routine oxalate coprecipitation method and citrate Sol-Gel method, studied much technics which would affect the quality of power, constituted the best preparation technics. Simultaneity, we researched the routine mellow and stearate Sol-Gel method systematically. At last compared the four methods and the power prepared, and interpreted the difference of the power from the mechanism of the grain forming. This thesis includes the following contents:Improved on the routine oxalate coprecipitation method, chosen the Ba(NO₃)₂ and C₃₆H₇₀O₄Ba as raw material which is low poisonous and cheaper, canceled the process that adding ammonia to adjust the system's pH value. This not only reduced the cost, enhanced the security, made the operation simpler, but also is fit for the large scale production. Based on the theory and the experiments, the best technics is that: the solution pH value is about 3, laying 4 hours at 80 ℃, the precipitator added speed is 15ml/min, and the dispersant is glycol. The synthesizing of BaTiO₃ power completed at 700 ℃. At last, we obtained the square crystalloid BaTiO₃ power, the grain average size is about 30nm, the grain is isotropy, and the power has good hot steady character and good disperse character. That is can't compared by the routine oxalate method.Perfected the rising citrate Sol- Gel method, we could't introduce H⁺ and NO₃^- in the preparation process. This not only made the operation simpler, enhanced the...