Effect of ZnO doping on microstructural and electrical properties of SnO<sub>2sub>-Ta<sub>2sub>O<sub>5sub> based varistors
- 作者：Jianfeng He<sup>asup> ; Zhijian Peng<sup>asup><sup> ; sup><sup>pengzhijian@cugb.edu.cnsup> ; Zhiqiang Fu<sup>asup> ; Chengbiao Wang<sup>asup> ; Xiuli Fu<sup>bsup><sup> ; sup><sup>xiulifu@bupt.edu.cnsup>
- 关键词：84.32.Ff ; 61.72.&minus ; y
- 刊名：Journal of Alloys and Compounds
- 出版年：2012
- 期刊代码：45_09258388
- 类别：ms
- 出版时间：5 July, 2012
- 卷：528
- 期：Complete
- 页码：79-83
- 文件大小：747 K
摘要
SnO<sub>2sub>-Ta<sub>2sub>O<sub>5sub> based varistors doped with 0-2.0 mol%of ZnO were prepared by sintering the samples at 1450 掳C for 2 h with conventional ceramic processing method. The doping effect of ZnO on the microstructural and electrical properties of the as-prepared SnO<sub>2sub>-Ta<sub>2sub>O<sub>5sub> based varistor ceramics was investigated. The change in SnO<sub>2sub> lattice parameter and EDX analysis both confirmed the doping of Zn ions into SnO<sub>2sub> grains, although the identified phase was only SnO<sub>2sub> (cassiterite) by X-ray diffraction in detection limit. The microstructure observation indicated that the doped ZnO can facilitate the sintering of the varistor ceramics. The measured electric-field/current-density characteristics of the samples revealed that the nonlinear exponents and varistor voltage increased with increasing doping amount of ZnO when the ZnO content was no more than 0.5 mol%; and more addition of ZnO would cause a decrease in nonlinear exponent and varistor voltage of the ceramic varistors.