Sb_2O_3掺杂对Pr_6O_11压敏电阻微结构和电学性能的影响

Effect of Sb_2O_3 Doping on the Microstructure and Electrical Properties of Pr_6O_11 Varistors

采用传统陶瓷工艺制备了Sb2O3掺杂的Pr6O11压敏电阻,并利用现代分析测试技术对其微结构和电学性能进行了研究。样品的相结构比较简单,除了Pr6O11主相外,未发现明显的第二相。样品的相对密度及晶粒尺寸随着Sb2O3掺杂量的提高而降低。非线性系数、压敏电压和晶界电阻都呈现出先降低后增加的趋势,非线性系数最高可达134。分析表明,Sb掺杂不与Pr6O11发生固相反应,其高温分解所产生的蒸汽压会降低Pr6O11压敏电阻的相对密度、晶粒尺寸及势垒高度,电学性能的变化要归结于相对密度、晶粒尺寸及势垒高度的共同作用。

Sb2O3 -doped Pr6O11 varistors were prepared by conventional ceramic processing techniques, the microstructure and electrical properties of the ceramic samples were studied using modern analysis and testing technology. The samples reveal simple microstructure consisting of only Pr6O11 phase, the secondary phase is not found. The relative density and grain size of the samples decrease with Sb2O3 content increasing. The nonlinear coefficient,breakdown voltage and grain boundary resistance first decrease and then increase Sb2O3 content increasing,the nonlinear coefficient can reach up to 134. It is proposed that Sb doping do not react with Pr6O11 ,the vapor pressure produced by decomposed Sb2O4 can reduce the relative density,grain sizes and barrier height of the samples,the change of electrical properties can be attributed to the combined action of relative density,grain sizes and barrier height.