低温烧结多层片式ZnO压敏电阻内电极Ag扩散对电性能的影响

Effect of in Inner Electrode Ag Diffusion on Electric Properties of Low Firing Multilayer Chip Zinc Oxide Varistor

研究了低温烧结多层片式ZnO压敏电阻的Pd-Ag内电极中Ag扩散对电性能的影响.发现当含Ag量不超过90%时,仍具有较好的电性能;但含Ag量再继续增加,电性能逐渐变差,内电极为纯Ag时,电性能严重恶化.反映晶界势垒电容的电容量随含Ag量的增加而减小.伏安特性和复数阻抗分析表明,随着内电极中含Ag量增加,Ag扩散进入ZnO晶格加剧,降低了施主浓度,导致ZnO晶粒电阻过分增大,而使多层片式ZnO压敏电阻的电性能劣化.

Effect of Ag diffusion of Pd-Ag inner electrode on electric properties of multilayer chip ZnO varistor was studied. The results show that Ag contents in inner electrode play a very important role in the electric properties of multilayer chip ZnO varsitor. When the Ag content is less than 90%, the properties are good, but when deteriorate with the increase of the Ag content. the Ag content is more than 90%, the properties And the properties of MLCV having pure Ag inner electrode are the worst. The capacitance reflecting the grain-boundary barrier capacitances decreases with the increase of Ag content. The analyses of V - I characteristic curves and complex impedances indicate that, during the co-firing process of the ceramic and inner electrode, with the increase of Ag content in inner electrode, the velocity of Ag diffusing in the ZnO lattice will speed, and the grain resistance increases excessively, and the electric properties of MLCV deteriorate.