ZnO-玻璃系压敏电阻老化特性研究

Research on Degradation Characteristics of ZnO-glass Varistors

研究了ZnO–玻璃系压敏电阻的直流老化特性、交流老化特性和大电流冲击老化特性。在恒定直流偏压作用下,ZnO–玻璃系压敏电阻伏–安特性出现非对称性蜕变,非欧姆特性降低。在交流偏压作用下,ZnO–玻璃系压敏电阻伏–安特性出现对称性蜕变。在脉冲大电流作用下,其伏安特性也呈现出非对称性蜕变。适当的低熔点氧化物和一价离子掺杂可改善样品的老化性能。还利用原子缺陷势垒模型对几种老化现象进行了理论分析。

Studied were the degradation characteristics of ZnO-glass varistors under a DC stress, an AC stress or an impulse load. The voltage-current characteristics of ZnO-glss varistors were deformed asymmetrically under a DC bias, and deformed symmetrically under an AC bias, characterized that nonlinear coefficients of samples decreased. The V-I curve was also deteriorated asymmetrically after large current impulse. The aging properties could be improved by doping a proper amount of low melting point oxides and mono-valent ions. The aging mechanisms were investigated by using atomic defect barrier model.