Effect of CeO_2 on Electrical Properties of (Nb,Mn)-Doped TiO_2 Varistor Ceramics  

作　　者：王茂华 胡克鳌 赵斌元 张南法 

机构地区：[1]State Key Laboratory of MMCs, Shanghai Jiaotong University, Shanghai 200030, China [2]Changzhou

出　　处：《Journal of Rare Earths》2005年第6期706-709,共4页稀土学报（英文版）

摘　　要：The electrical properties of TiO2-based varistor ceramics with different amount of CeO2 were investigated by measuring the properties of V-I, permittivity, density and boundary defect barriers. It is found that an optimal composition doped with 0.7% CeO2 exhibits the highest nonlinear coefficient of 10.5, the highest breakdown voltage of 12.77 V·mm^-1, the ultrahigh permittivity of 82900（measured at 1 kHz）, and the highest density of 4.15 g·cm^-3, which is consistent with the highest and narrowest grain-boundary defect barriers. In order to illustrate the grain boundary barriers formation in TiO2-Nb2O5-MnCO3-CeO2 varistor, an grain-boundary defect barrier model was also introduced.The electrical properties of TiO2-based varistor ceramics with different amount of CeO2 were investigated by measuring the properties of V-I, permittivity, density and boundary defect barriers. It is found that an optimal composition doped with 0.7% CeO2 exhibits the highest nonlinear coefficient of 10.5, the highest breakdown voltage of 12.77 V·mm^-1, the ultrahigh permittivity of 82900（measured at 1 kHz）, and the highest density of 4.15 g·cm^-3, which is consistent with the highest and narrowest grain-boundary defect barriers. In order to illustrate the grain boundary barriers formation in TiO2-Nb2O5-MnCO3-CeO2 varistor, an grain-boundary defect barrier model was also introduced.

关 键 词：VARISTOR defect barrier model TIO2 CEO2 electrical properties rare earths 

分 类 号：TQ174.1[化学工程—陶瓷工业]