La2O3的掺杂对氧化锌压敏陶瓷电性能的影响

Effect of La2O3 Doping on Electrical Properties of ZnO Varistor Ceramics

采用传统固相法制备稀土氧化物La2O3掺杂的ZnO压敏陶瓷。采用X线衍射(XRD)、扫描电子显微镜(SEM)和压敏电阻直流参数仪对样品的物相、显微组织及电性能进行分析。结果表明,随着La2O3掺杂量的增加,ZnO压敏陶瓷电位梯度单调递增,非线性系数先增加后减小,而漏电流呈现先减小后增大的变化趋势。综合衡量ZnO压敏电阻的各项性能指标发现,在1000℃烧结温度下,La2O3的质量分数为0.25%时,ZnO压敏电阻的综合性能最好,其电位梯度为532.2 V/mm,非线性系数为41.6,漏电流为3.3μA。

The ZnO varistor ceramics with rare earth oxide La2O3 doping were prepared by conventional solid state reaction method.The phase compositions,microstructure and electrical properties of the as-prepared samples were investigated by X-Ray diffraction(XRD),scanning electron microscope(SEM)and varistor DC parameter tester.The results show that with the increase of La2O3 doping content,the potential gradient of ZnO varistor ceramics increases monotonically,the nonlinear coefficient initially increases and then decreases,while the leakage current first decreases and then increases.According to the comprehensive evaluation of the specifications of ZnO varistor,when the doping content of Gd2O3 is 0.25%(mass fraction)at the sintering temperature of 1000℃,the comprehensive performance of the ZnO varistor is the best,and the potential gradient,the nonlinear coefficient and the leakage current are 532.2 V/mm,41.6 and 3.3μA,respectively.