La替代对Bi_2O_3-ZnO-Nb_2O_5陶瓷介电性能的影响  

Dielectric properties of La-doped Bi_2O_3-ZnO-Nb_2O_5 based ceramics

作　　者：刘璞凌[1] 丁士华[1] 杨同青[1] 沈波[1] 姚熹[1] 

机构地区：[1]同济大学功能材料研究所,上海200092

出　　处：《功能材料与器件学报》2007年第1期78-81,共4页Journal of Functional Materials and Devices

基　　金：国家重大基础研究计划(No.2002CB613302)

摘　　要：研究了A位La3+替代对Bi2O3-ZnO-Nb2O5(BZN)陶瓷结构和介电性能的影响。当La替代量x<0.5时,陶瓷相结构为单一的立方焦绿石相。随着La替代量的增加,陶瓷样品的晶粒尺寸和密度逐渐减小。低温下的介电弛豫现象随着La替代量的增加也发生有规律的变化,介电常数逐渐减小,弛豫峰峰形逐渐宽化,峰值温度向低温方向移动。与La替代量为0.1、0.15、0.3和0.5相对应的弛豫峰的峰值温度分别为-95℃、-99℃、-109℃和-112℃。The structure and dielectric properties of La -doped Bi2O3 -ZnO -Nb2O5 ceramics were investigated. The sample exhibits a single cubic pyrochlore phase at La^3 ＋ substitution 〈 0.5. The grain size and density values decrease with the increasing of La^3 ＋ substitution. The relaxation behavior under low temperature exhibits a regular change with La^3＋ substitution. The dielectric constant of BZN samples decrease and the peak temperature of dielectric relaxation moves towards low temperature with the increasing of La^3＋ substitution. When the substitution content of La^3＋ increase from 0.1 to 0.5, the peak temperature moves from - 95℃ to - 112℃ at 1 MHz, respectively.

关 键 词：BZN陶瓷 立方焦绿石相 介电弛豫 

分 类 号：TM28[一般工业技术—材料科学与工程]