Fabrication and electrical characteristics of flash-sintered SiO2-doped ZnO-Bi2O3-MnO2 varistors

• Main Authors: Pai Peng, Yujun Deng, Jingpeng Niu, Liyi Shi, Yunzhu Mei, Sanming Du, Juan Liu, Dong Xu
• Format: Article
• Language: English
• Published: SpringerOpen 2020-07-01
• Series: Journal of Advanced Ceramics
• Subjects: flash sintering; SiO2 additive; ZBMS varistors; electrical properties
• Online Access: https://doi.org/10.1007/s40145-020-0404-7

Abstract The dense ZnO-Bi2O3-MnO2-xSiO2 (ZBMS) varistors for x = 0, 1, 2, 3 wt% were fabricated by flash sintering method under the low temperature of 850 °C within 2 min. The sample temperature was estimated by a black body radiation model in the flash sintering process. The crystalline phase assemblage, density, microstructure, and electrical characteristics of the flash-sintered ZBMS varistors with different SiO2-doped content were investigated. According to the XRD analysis, many secondary phases were detected due to the SiO2 doping. Meanwhile, the average grain size decrease with increasing SiO2-doped content. The improved nonlinear characteristics were obtained in SiO2-doped samples, which can be attributed to the ion migration and oxygen absorption induced by the doped SiO2. The flash-sintered ZBMS varistor ceramics for x = 2 wt% exhibited excellent comprehensive electrical properties, with the nonlinear coefficient of 24.5, the threshold voltage and leakage current of 385 V·mm−1 and 11.8 µA, respectively.