Abstract： We investigate the effects of Er2O3 on electrical properties of the SnO2.CoO.Ta2O5 varistor system sintered at 1400°C. It is found that all the samples have excellent nonlinear electrical characteristics and the sample with 0.50 mol% Er2O3 has the best nonlinear electrical property and the highest nonlinear coefficient (α = 43.7). The high nonlinear coefficient value obtained in the system indicates that the SnO2-based varistor is a candidate for ZnO-based varistors in commercial applications. Er2O3 additive can significantly affect the average grain size. With increasing Er2O3 concentration from 0.10 mol% to 1.00 mol%, the average grain size decreases from 21.2μm to 10.6μm, the breakdown electrical field increases from 208 V/mm to 459 V/mm, and the relative electrical permittivity decreases from 2440 to 1210. The reason that the grain size decreases with increasing Er2O3 concentration is explained. Also, we present a modified defect barrier model to illustrate the grain-boundary barrier formation of Er2O3-doped SnO2 based varistors.
(Conductors, resistors (including thermistors, varistors, and photoresistors))
引用本文:
WANG Chun-Ming;WANG Jin-Feng;CHEN Hong-Cun;SU Wen-Bin;ZANG Guo-Zhong;QI Peng. Effects of Er2O3 on Electrical Properties of the SnO2.CoO.Ta2O5 Varistor System[J]. 中国物理快报, 2004, 21(4): 716-719.
WANG Chun-Ming, WANG Jin-Feng, CHEN Hong-Cun, SU Wen-Bin, ZANG Guo-Zhong, QI Peng. Effects of Er2O3 on Electrical Properties of the SnO2.CoO.Ta2O5 Varistor System. Chin. Phys. Lett., 2004, 21(4): 716-719.
2004, Vol. 21 
