钛酸钡的合成、结构与性质研究

本文分别以四氯化钛和氯化钡为钛源和钡源,用NaOH作沉淀剂,在pH大于13.5的条件下合成出了BaTiO_3。反应条件为:反应温度为90℃,时间4小时,反应物料Ba:Ti=0.8-10.5(摩尔比);X-射线物相分析表明,产品为立方晶系,a=4.003。电镜观察,粒度均匀,大小为0.2-0.3μm。为除去产品中微量的碳酸盐杂质,用稀盐酸对产品进行后处理,(处理液用Ys-1和Ys-2代替),结果发现,待Ys-2处理后,产品由立方晶系变成了更稳定的四方晶系。差热分析结合X-rag相分析表明,立方晶系的钛酸钡在750℃转变成了四方晶系。这同用Ys-2处理的结果是相吻和的。另外,本文还就反应温度、反应时间、沉淀剂的量等对产品的影响作了详细研究。

The Synthesis Structure and Properties of Barium titanate

The Barium titanate was synthesiged by copptn method .TiCl4and BaCl2 · 2H2O were used as starting materials NaOH as Precipitating agont. First, a hydrolysed product of a Barium and Titanium was prepared in an ag.alkaline solution having a pH of not less than 13.5.Then the aq. solution was continvously reacted at the reaction tempeature of 90℃ for Four hours.Comparing this x-rag diffraction pallerm of the product thus made with a ASTM Card , it was Confinmed that the BaTiO3thus made was of Cubic system. An electron microscope Anal. Shown that the particle size of BaTiO3fine powder thus made was 0. 2- 0. 3μm . DTA Combined with x- rag: anal shown that Cubic system BaTiO3was translated into tetragonal system at the temperature of 745 ℃.