稀土氧化物掺杂对ZnO-Bi_2O_3系压敏陶瓷导电过程的影响

The Influence of Rare-earth Oxides on Conduction Process of ZnO Varistor Ceramics

掺杂稀土氧化物可改变ZnO晶粒的尺寸,从而改变了等效偏析层的厚度,并分析了偏析层在导电过程中的作用。发现未掺杂试样的导电过程由晶界偏析层控制,而稀土氧化物Ce2O3、Y2O3掺杂后,由于晶粒尺寸的下降,试样的导电过程转变为界面态能级控制。因此对于多掺杂体系或小晶粒体系,应考虑偏析层对压敏陶瓷宏观的电气性能的影响。

ZnO grain size could be changed by the adulteration of rare earth oxides so that the thickness of equivalent segregated layer was changed. The influence of segregated layer in conduction process was analyzed. It is found that the conduction process of sample without rare earth oxides is controlled by grain boundary segregation. While, after the adulteration of Ce2O3 and Y2O3, the conduction process was controlled by interface states levels for the decrease of grain size. So, for the adulteration system or small grain system, the effect of the segregated layer to the macro electrical performance of varistor ceramics should be considered.