LIU Wenjin, AI Jianping, SU Xiaoxuan, WU Yulong, LI Wenkui, CHENG Lihong

(Jiangxi Key Laboratory of Surface Engineering, Jiangxi Science and Technology Normal University, Nanchang 330038, Jiangxi, China)

Abstract: The high performance ZnO-Bi₂O₃-based ceramics formula whose Bi₂O₃ and Sb₂O₃ pretreated at a ratio of 1︰1 was used to decrease the volatilization of Bi₂O₃ and Sb₂O₃ which has low melting point, to reduce the sintering temperature below 1000 ℃ and improve the microstructure uniformity of the ceramic samples which were obtained by ball milling. The varistor ceramic samples were prepared with the traditional method. The results show that the samples with Bi₂O₃ and Sb₂O₃ pretreated have less porosity, higher density, voltage in the range of 460-600 V/mm, nonlinear coefficient in the range of 40-60, leakage current less than 1 μA. Pretreatment was effective in preventing the volatilization of Bi₂O₃ and Sb₂O₃. The results can provide theoretical support for the manufacture of multilayer ZnO varistors with silver (Ag) as inner electrode.
Key words: ZnO; varistor ceramics; microstructure; electrical properties