MgO掺杂对SnO_(2)压敏电阻性能的影响  

The Effect of MgO Doping on the Properties of SnO_(2)-Based Varistor

作　　者：孙岩 任鑫 吴育聪 杨莉禹 宁宇 姚政 施利毅[1] SUN Yan;REN Xin;WU Yucong;YANG Liyu;NING Yu;YAO Zheng;SHI Liyi(Nano-Science and Technology Research Center,College of Sciences,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学理学院纳米科学与技术研究中心,上海200444

出　　处：《电瓷避雷器》2024年第5期79-83,共5页Insulators and Surge Arresters

基　　金：上海市自然科学基金(编号:17ZR1410300)。

摘　　要：采用传统的SnO_(2)+CoO+Nb_(2)O_(5)+Cr_(2)O_(3)压敏电阻体系,深入研究了MgO掺杂对SnO_(2)基压敏电阻综合电性能和微观形貌的影响。结果表明,当MgO掺杂量为0.5%(摩尔分数)可获得最佳的电性能,非线性系数为32,电压梯度为284.3 V/mm,漏电流为7.1μA。这是因为Mg2+作为受主掺杂剂,提高了表面态密度,当MgO的掺杂量超过SnO_(2)样品的溶解度极限时,在晶界处形成尖晶石,由于钉扎效应阻止了ZnO晶粒的生长,因此晶粒尺寸减小并形成更多晶界,有效提高了SnO_(2)压敏电阻的综合电性能。此外MgO的掺杂使得晶粒尺寸分布更均匀,降低了孔隙率,提高了样品的烧结密度。The effects of different MgO contents on the microstructure and electrical properties of SnO_(2)-based varistor were investigated by adopting the traditional SnO_(2)+CoO+Nb_(2)O_(5)+Cr_(2)O_(3)varistor system.The results show that the best electrical properties can be obtained when the MgO content is 0.5%(mole fraction),with the nonlinear coefficient of 32,the breakdown voltage gradient of 284.3 V/mm,and the leakage current density of 7.1μA.Because Mg^(2+)acts as an acceptor dopant,increasing the surface state density,when the doping amount of MgO exceeds the solubility limit of the SnO_(2)sample,spinners are formed at the grain boundaries,which prevents the growth of ZnO grains due to the pinning effect.Therefore,the grain size is reduced and more grain boundaries are formed,which effectively improves the comprehensive electrical properties of the SnO_(2)varistor.In addition,the doping of MgO makes the grain size distribution more uniform,reduces the porosity,and increases the sintered density of the samples.

关 键 词：MgO掺杂 SnO_(2)压敏电阻 固溶体 电气性能 

分 类 号：TM54[电气工程—电器]