%0 Journal Article
%T Electrical Properties and Kinetic of Crystalline Grain Growth of Low-voltage ZnO Varistor Doped with Zn-B Glass
%A WAN Shuai
%A Lv Wen-Zhong
%J 无机材料学报
%D 2010
%I Science Press
%R 10.3724/sp.j.1077.2010.00157
%X The effects of Zn-B glass additive on microstructure and electrical properties of low-voltage ZnO varistor were studied. The results show that ZnO varistor with x=0.1wt% obtains the optimal nonlinear electrical properties: E1mA=36.7V/mm, α=30.4, IL=0.1μA. The grain growth mechanism of low-voltage ZnO varistor doped with Zn-B glass is also investigated in terms of the phenomenological kinetic of crystalline grain growth. Based on the theory, the grain growth kinetic exponent n and apparent activation energy Q are calculated as 4.54 and 316.5kJ/mol for ZnO ceramics varistor sintered at the temperature below 1000℃. The grain growth mechanism is that non-melting Zn-B glass pins the ZnO grain boundaries, which inhibits the grain growth of ZnO varistor. However, n and Q value are 2.92 and 187kJ/mol at the temperature higher than 1000℃. It indicates that melting Zn-B glass wetting the ZnO grain boundaries creates a liquid phase sintering mechanism, which accelerates the grain growth of ZnO varistor.
%K Zn-B glass
%K varistor
%K electrical properties
%K kinetic exponent
%K apparent activation energy
%U http://www.jim.org.cn/fileup/PDF/20100209.pdf