Effect of Composite Additives on ZnO Varistor Ceramics
ZnO-based varistor ceramics were prepared by sintering ZnO powders with minor additives that were synthesized by standard ball milling, high energy ball milling for 10 h, and pyrogenic decomposition of nitrate. The microscopic structure and composition were analyzed by SEM and XRD respectively, and the electrical properties were investigated by a DC parameter instrument for varistors. Influences of composite additives on composition, microstructure, and electrical properties of ZnO-based varistors were studied. The ZnO varistor with optimum performance is prepared by the pyrogenic decomposition method and it has an average grain size of 5 µm and possesses a varistor voltage of about 561 V/mm, non linear coefficient of 75, and leakage current of 0.45 µA.
Chengming Li, Chengbao Jiang, Zhiyong Zhong and Yichun Zhou
J. F. Zhu et al., "Effect of Composite Additives on ZnO Varistor Ceramics", Materials Science Forum, Vol. 687, pp. 21-25, 2011