SnO2-Sb2O3基压敏陶瓷致密化及脉冲电流耐受特性

实验研究了TiO₂、Co₃O₄、Cr₂O₃、Ni₂O₃和MnO掺杂对SnO₂-Sb₂O₃基压敏陶瓷材料微观结构和电性能的影响. 研究结果表明, TiO₂和Co₃O₄促进SnO₂陶瓷烧结致密化, 根据XRD图谱分析结果, Co₃O₄与SnO₂反应形成了Co₂SnO₄晶相, TiO₂则固溶于SnO₂晶相;Sb元素的引入能够促进SnO₂晶粒的半导化;复合添加Cr₂O₃、Ni₂O₃和MnO可以有效提高材料的电压非线性特性和脉冲电流冲击耐受能力. 获得电性能接近实用化的SnO₂压敏陶瓷样品, 其压敏电压V_1mA约为350V/mm, 非线性系数α达到50, 漏电流小于5μA, 并且在8/20μs脉冲电流冲击试验中,直径14mm的样品能够经受2kA的脉冲峰值电流.

Densification and Surge Current Performance of SnO2-Sb2O3 Based Varistor Ceramics

Influence of TiO₂, Co₃O₄, Cr₂O₃, Ni₂O₃ and MnO dopings on the microstructure and electrical properties of SnO₂-Sb₂O₃ based varistor ceramic materials was investigated. It is found that TiO₂ and Co₃O₄ are effective dopants for improving densification of SnO₂ ceramics. According to XRD analysis, Co₂SnO₄ crystal phase are formed by the reaction between Co₃O₄ and SnO₂, and TiO₂ is dissolved into the SnO₂ phase. Doping of Sb₂O₃ can improve the semiconducting processes of SnO₂ grains. Co-doping Cr₂O₃, Ni₂O₃ and MnO is efficient to improve the nonlinear property and surge current withstanding performance of the materials. The samples with a diameter of 14mm have a nonlinear coefficient (α) of about 50, a breakdown electric filed of about 350V/mm and a leakage current of less than 5μA, and the withstanding surge peak current of 8/20μs waveshape is about 2kA, which meet practical requirement.