拓扑化学法制备棒状(KxNa1-x)NbO3粉体  

Topo-chemical Synthesis of Rod-like(K_xNa_(1-x))NbO_3 Particles

作　　者：李月明[1] 刘虎[1] 沈宗洋[1] 王竹梅[1] 洪燕[1] 李润润[1] 廖润华[1] 

机构地区：[1]景德镇陶瓷学院材料科学与工程学院,江西省先进陶瓷材料重点实验室,景德镇333403

出　　处：《人工晶体学报》2011年第4期911-916,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(50962007);江西省自然科学基金(2009GZ0063);江西省主要学科学术和技术带头人培养计划项目(2010DD0110);江西省教育厅青年科技基金(GJJ095333)资助项目

摘　　要：以Na2CO3、K2CO3、Nb2O5和KCl为原料,采用拓扑化学反应法合成出一维方向生长钙钛矿结构的棒状KxNa1-xNbO3(KNN)粉体。首先采用熔盐法合成出棒状的前驱体K2Nb8O21晶体,系统研究了Nb2O5与KCl的起始质量比、合成温度对K2Nb8O21晶体显微结构和形貌的影响,研究发现当Nb2O5与KCl的质量比为3/8,850℃下保温3 h可以获得长度为80～100μm,直径为3～8μm的棒状K2Nb8O21晶体,且晶体沿[100]方向生长;然后以棒状的前驱体K2Nb8O21为模板晶粒,采用拓扑化学反应法制备出棒状KNN晶体,研究了Na2CO3的添加量、烧成温度和保温时间对棒状KNN晶体显微结构和形貌的影响。结果表明:添加过量10wt%的Na2CO3,在900℃下保温3 h可以获得沿[001]方向生长的棒状KNN晶体,其中K/Na=47.31/52.69,接近1/1,其长度和宽度分别为30～50μm和2～6μm。Perovskite one-dimension rod-like（KxNa1-x）NbO3（KNN） powders were prepared by topo-chemical reaction method using Na2CO3,K2CO3,Nb2O5 and KCl as raw materials.First,rod-like precursor K2Nb8O21 was synthesized by molten salt method.The effects of Nb2O5/KCl mass ratio and synthesis temperature on microstructure and topography of K2Nb8O21 precursor were investigated,and rod-like K2Nb8O21 crystal with 80-100 μm length and 3-8 μm width could be obtained when the Nb2O5/KCl mass ratio was 3/8 and synthesized at 850 ℃ for 3 h.The rod-like K2Nb8O21 crystal was grown along ／ crystallography direction.Second,rod-like KNN was obtained by topo-chemical reaction using precursor K2Nb8O21 as template.The effects of Na2CO3 addition,synthesis temperature and soaking time on microstructure and topography of KNN crystal were investigated,and rod-like KNN crystal（K/Na=47.31/52.69） growth along ／ direction with 30-50 μm length and 2-6 μm width can be obtained when 10wt% excess Na2CO3 was added and synthesized at 900 ℃ for 3 h.

关 键 词：熔盐法 拓扑化学反应法 铌酸钾钠 

分 类 号：O614[理学—无机化学]