摘要
采用水溶液直接沉淀法成功制备了LaF3纳米粉体.用透射电子显微镜（TEM）观察了粒子形貌及粒度,粒子呈球形,粒径范围在10～20 nm之间,粉体单分散性良好.用X射线衍射（XRD）分析得到的平均粒径16.7 nm.采用真空高压固结法在真空度10^-4 Pa条件下常温加压至1GPa制备了纳米LaF3块体材料.采用交流阻抗谱研究了纳米LaF3的室温离子电导率,发现纳米LaF3的室温离子电导率（10^-5 S·cm^-1）和单晶LaF3的室温离子电导率（10^-6 S·cm^-1）相比有明显提高.观察到由于纳米材料的弛豫引起电导率随测试次数增大的现象.
Nanocrystalline powder of LaF3 was synthesized by a method of direct precipitation from water solution. Particle size and shape of LaF3 nanocrystalline powder was analysed with TEM. Particles were mainly spherical with narrow particle size distribution （10- 20 nm）. The average particle size analysed with XRD is 16.7 nm. Nano-LaF3 bulk material was prepared by compacting the powder to 1 GPa at room temperature and a vacuum of 10-4 Pa. The ionic conductivity of nano-LaF3 bulk material was studied with complex impedance spectra at room temperature. The ionic conductivity of nano-LaF3 bulk material （10^-5 S·cm^-1） at room temperature is significantly increased compared to that of single crystal LaF3 （ S·cm^-1）. A special phenomenon was observed first time that the ionic conductivity increased gradually with multiple testing which resulting in relaxation.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2006年第2期179-183,共5页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金资助项目(59872031)
关键词
纳米晶
纳米LaF3块体材料
离子电导率
复阻抗谱
稀土
nanocrystalline
nano-LaF3 bulk material
ionic conductivity
complex impedance spectra
rare earths
