Influence of Y2O3 on Electrical Properties and Dielectric Characteristics in ZnO Based Varistor Ceramics
The voltage gradient of ZnO based varistor is usually opposite to the average grain size. It has been reported that the growth of ZnO grains could be inhibited by doping with rare-earth oxides. In this paper the electrical properties and dielectric characteristics of ZnO based varistor ceramics with various Y2O3 additions are investigated. The voltage gradient of varistor samples markedly increase with Y2O3 contents increasing. However, the leakage currents and nonlinear coefficients of the samples are deteriorated at the same time. Measurement results show the dielectric constant and dissipation factor of varistors are affected by the doping ratio of yttrium oxide, and the decrement of dielectric constant as the Y2O3 addition increasing could be attributed to the internal boundary layer capacitance (IBLC) effect. Meanwhile, the relaxation peak of dissipation factor shifting to lower frequency may be related to the variation of intrinsic defects in ZnO grains.
ZnO varistor ceramic yttrium ozide electrical property dielectric characteristics
Jun LIU Jinliang HE Jun HU Wangchen LONG Fengchao LUO
Department of Electrical Engineering, Tsinghua University, Beijing 100084, CHINA
国际会议
哈尔滨
英文
1150-1153
2009-07-19（万方平台首次上网日期，不代表论文的发表时间）