La Doped Layered Structure low-voltage ZnO Varistor
Double-layered,low-voltage ZnO varistors (including layer A and layer B) have been fabricated by feeding two kinds of ZnO powders into a die using dry extrusion molding.The samples are examined by using energy dispersive X-ray spectroscopy (EDS),electron probe microanalysis (EPMA),scanning electron microscope (SEM) and DC electrical measurements.EDS and EPMA data indicate that doped elements only exists in layer A,the results of SEM indicated that secondary phases are formed at grain boundaries in layer A,not found in layer B.It is found that the electrical properties of low-voltage varistor are improved without reducing thickness and changing energy absorption capabilities.The higher nonlinearity coefficients,the lower breakdown fields and leakage currents of layered structure low-voltage ZnO varistor,as compared to those of ZnO varistor fabricated from the conventional route.The improved current-voltage properties are attributed to the band structure difference in both sides of grains,due to the different ion concentration and species in both sides of grain boundary.Double-laycrcd structure varistor also has more simpler prepared technology than multilayer chip varistor.
ZnO Varistor Layered structure Low-voltage Electrical properties
Xing Gao Guoyou Gan Lihui Wang Jikang Yan Jianhong Yi Jinghong Du Jiamin Zhang
Faculty of Materials Science and Engineering,Kunming University of Science and Technologe,Kunming 65 CNMC Ningxia Orient Group Co.,Ltd.,Shizuishan,Ningxia 753000,China
国际会议
The Seventh China International Conference on High-Performance Ceramics (第七届先进陶瓷国际研讨会(CICC-7))
厦门
英文
1263-1267
2011-11-04（万方平台首次上网日期，不代表论文的发表时间）