The effect of BaTiO3 content on the microstructure and electrical properties of Bi2O3/ZnO varistor materials

Influence of Sintering Temperature and ZrO2 Dopants on the Microstructure and Electrical Properties of Zinc Oxide Varistors

“…E 1mA and I L were obtained using voltage generator and current meter(10xbc, Huatian, China). The nonlinear coefficient (α) can be calculated as follow: [2], [16], [17]…”

“…The influence of ZrO 2 content and sintering temperature on the average grain size of ZnO varistors was obtained by linear intercept method [14], [17], which can be expressed as follow: draw a straight line in the microscope, count the number of grains intercepted in the straight line, then the average grain size can be obtained as d = L/M , in which L is the length of the straight liner and M is the ZnO grain number.…”

“…a low residual voltage ratio [10]- [13], [15], [19]. In addition, leakage current is also an important parameter of ZnO varistors, which has a great influence on the service life of MOAs [17], [20]- [23]. Thus, it is of great significance to improve the voltage gradient of ZnO varistors with a small leakage current, a high non-linear coefficient and a low residual voltage ratio.…”

“…Exist studies in [33] found that ZrO 2 can improve the voltage gradient of ZnO varistors, but till now, little work has been done to study the effects of ZrO 2 addictives on the element distribution, crystal phase and electric characteristics of ZnO varistors. It has been reported that sintering temperature can effectively influence the electric characteristics and microstructure of ZnO varistors [13], [2], [17], [18], but little has been done to study the combined effects of sintering temperature and ZrO 2 addictives.…”

“…Reagent-grade raw materials were used, the powders were firstly mixed in specific proportion with deionized water, then the mixed sizing agent was subjected to high energy ball milling for 30min. After milling, spraying granulating process was applied and the mixed powder was pressed at discs of 40mm diameter and 20mm thickness [17]. The density of the pressed discs was 3.2g/cm 3 .…”