镧掺杂钛酸钡粉体的水热改性  

HYDROTHERMAL MODIFICATION OF La-DOPED BaTiO_3 POWDERS

作　　者：蒲永平[1,2] 庄永勇[1,2] 吴海东[1] 许宁[1] 刘建科[1] 

机构地区：[1]陕西科技大学材料科学与工程学院,西安710021 [2]教育部轻化工助剂化学与技术重点实验室,西安710021

出　　处：《硅酸盐学报》2010年第7期1253-1257,共5页Journal of The Chinese Ceramic Society

基　　金：教育部科学技术研究重点项目(209126);陕西省科技厅工业攻关项目(2010K10-14);陕西省教育厅科研专项基金(112H011);陕西科技大学研究生创新基金资助项目

摘　　要：以固相法合成的BaTiO3粉体和La(NO3)3溶液为反应前驱物,NaOH为矿化剂,对BaTiO3粉体表面进行镧掺杂水热改性。利用X射线衍射仪、扫描电镜、Fourier红外光谱仪和透射电镜等研究了水热处理后BaTiO3粉体及陶瓷的相组成、晶粒尺寸、颗粒形貌及电性能。结果表明:对不同镧掺杂浓度的BaTiO3粉体进行水热处理后,粉体粒径变小,粒度分布范围变窄,颗粒形貌变得圆整,实现了高温、高压条件下的水热"整形"作用。在BaTiO3粉体颗粒表层形成了一层约50nm厚的富镧层,实现了高温高压下对BaTiO3陶瓷粉体的改性。将改性后的BaTiO3粉体制成陶瓷,其室温电阻率测试结果表明,经水热处理后的粉体改善了镧在钛酸钡陶瓷中的掺杂均匀性,掺杂半导化浓度范围加宽。The surface of La-doped barium titanate（BaTiO3） powders was modified by a hydrothermal process using BaTiO3 powders,which prepared by solid phase synthesis method,and La（NO3）3 solutions as precursors,and NaOH solutions as mineralizer.The phase composition,crystalline grain size,grain morphology and electric property of BaTiO3 powders and ceramics after hydrothermal treatment were investigated by X-ray diffraction,scanning electron microscope,Fourier transform infrared spectrophotometer and transmission electron microscope,etc.The results show that the product with finer particle size and narrower size distribution can be obtained after hydrothermal modification.The morphology of BaTiO3 particles becomes rounder achieving hydrothermal modification under high temperature and high pressure conditions.La layer with thickness of about 50 nm on the surface of BaTiO3 particles is formed by hydrothermal modification.The distribution of lanthanum in the La-doped BaTiO3 ceramics can be more homogeneous after hydrothermal treatment.The doping concentration range of semi-conductivity is broadened.

关 键 词：钛酸钡 镧掺杂 水热处理 均匀性 

分 类 号：TB34[一般工业技术—材料科学与工程]