Effect of CeO2 on the Electrical Properties of Ta2O5-doped TiO2 Capacitor-varistor Ceramics

摘要：

TiO2 varistors doped with 0.1 mol％ Ta and different concentrations of CeO2 were obtained by ceramic sintering processing at 1400 ℃. The effect of CeO2 on the nonlinear electrical behavior and dielectric properties of the Ta2O5-doped TiO2 ceramics were investigated. The nonlinear current (I)-voltage (V) characteristics of TiO2 are examined when doped with small quantities (0.1 -0.9 mol％) of CeO2. It is found that CeO2 affects the electrical properties and the dielectric properties of the TiO2-based varistors. The samples have the nonlinear coefficients (α) values of (3.0-5.0), breakdown voltages (10-30 V/tnm) and ultrahigh dielectric constants which is up to 105. A small quantities of CeO2 can improve the nonlinear properties of the samples significantly. It was found that an optimal doping composition of 99.4 mol％ TiO2-0.1 mol％ Ta2Os-0.30 mol％ CeO2 was obtained with low breakdown voltage of 14.2 V/mm, high nonlinear constant of 4.5, an ultrahigh electrical permittivity of 8.381.22x 105 (measured at 1 kHz) and low tan8 of 0.32, which is consistent with the highest grain boundary barriers of the ceramics. The theory of defects in the crystal lattice was introduced to explain the nonlinear electrical behavior of the CeO2-doped TiO2-based varistor ceramics.

关键词： Titanium oxide Varistors Electrical properties Microstructure

作者: Tianguo Wang Qun Qin Wenjun Zhang

作者单位: Department of Material Science and Engineering,Hubei University of Automotive Technology,Shiyan 4420 State Key Laboratory of Advanced Technology for Materials Synthesis & Processing,Wuhan University of

会议类型: 国际会议

会议名称: the 2011 International Conference on Key Engineering Materials(ICKEM 2011)(2011关键工程材料国际会议)

会议地点: 三亚

会议语种:英文

页码: 168-172

在线出版日期: 2011-03-25（万方平台首次上网日期，不代表论文的发表时间）