Microstructure and electrical properties of MgO-doped SnO2 varistor ceramics

作者:Hu Guangliang*; Zhu Jianfeng; Yang Haibo; Wang Fen
来源:Journal of Materials Science: Materials in Electronics , 2014, 25(2): 997-1002.
DOI:10.1007/s10854-013-1677-1

摘要

The effect of MgO addition on the properties of (Co, Nb, Cr)-doped SnO2 varistors was investigated. The samples with different MgO concentrations were fabricated by the conventional ceramic method and sintered at 1,250, 1,300, 1,350 and 1,400 A degrees C for 2 h. It was found that the nonlinear coefficient presented a peak value of 28 and lowest leakage current density of 7 mu A/cm(2) when 0.5 mol% MgO was added. The breakdown electrical field increased from 174 to 531 V/mm with increasing MgO from 0.0 to 2.0 mol%. The relative dielectric constant decreased with increasing MgO from 0.0 to 0.5 mol%, but increased with more MgO added. The dielectric loss decreased obviously in the case of low frequency with MgO added, and it had the lowest value when 0.5 mol% MgO added. The optimal samples were obtained by doping MgO with 0.5 mol% and sintering at 1,350 A degrees C.

全文