Synthesis and room temperature ionic conductivity of nano-LaF_3 bulk material  

作　　者：吴大雄 吴希俊 吕燕飞 王晖 

机构地区：[1]Institute of Material Physics and Microstructure, College of Materials and Chemical Engineering, Zhejiang University, Ha ngzhou 310027, China

出　　处：《中国有色金属学会会刊：英文版》2006年第4期828-832,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project(59872031) supported by the National Natural Science Foundation of China

摘　　要：The ionic conductivity (at room temperature) of nano-LaF3 bulk material and a new discovered phenomenon of increasing ionic conductivity caused by grain boundary relaxation activated by AC (alternating current) shocking were reported. Nano-crystalline powder of LaF3 with average grain size of 16.7 nm was synthesized with a method of direct precipitation from aqueous solution. Particle size and shape of LaF3 nano-crystalline powder were analyzed by XRD and TEM. Nano-LaF3 bulk material was prepared by compacting the powder to 1 GPa at room temperature and 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) at room temperature is significantly increased compared with that of single crystal LaF3 (10?6 S/cm). A special phenomenon is observed for the first time that the ionic conductivity increases gradually with AC scanning times.The ionic conductivity （at room temperature） of nano-LaF3 bulk material and a new discovered phenomenon of increasing ionic conductivity caused by grain boundary relaxation activated by AC （alternating current） shocking were reported. Nano-crystalline powder of LaF3 with average grain size of 16.7 nm was synthesized with a method of direct precipitation from aqueous solution. Particle size and shape of LaF3 nano-crystalline powder were analyzed by XRD and TEM. Nano-LaF3 bulk material was prepared by compacting the powder to 1 GPa at room temperature and 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） at room temperature is significantly increased compared with that of single crystal LaF3 （10^-6 S/cm）. A special phenomenon is observed for the first time that the ionic conductivity increases gradually with AC scanning times.

关 键 词：LAF3 纳米材料 纳米晶 离子电导性 阻抗谱 稀土 

分 类 号：TB383.1[一般工业技术—材料科学与工程]