【摘要】 理论上,SrTiO₃（以下简称STO）晶界层电容器介电常数取决于陶瓷片的晶粒大小、导电性、晶界绝缘层的厚度和介电常数.但对实际的STO晶界层陶瓷电容器研究发现,金属电极与STO陶瓷片的表面接触对电容器的电容和介电常数也有很大影响.研究表明,当电极/STO为非欧姆接触时,STO陶瓷片的电容和介电常数较小;当电极/STO为欧姆接触时,STO陶瓷片电容器的电容和介电常数增大.采用Ag浆制作电极时,通过调整烧制Ag电极的温度和时间,当T=880℃,t=3. 5 h时,STO电容器的介电性能达到最佳,ε_r=22 850,tgδ=1. 0%.更多还原

【Abstract】 Theoretically,dielectric constant of SrTiO₃（ hereinafter referred as STO） grain boundary layer capacitor depends on the grain size,conductivity,thickness and dielectric constant of the grain boundary insulating layer（ GBIL）. However,in this work,it was found that the electrical property of the contact between metallic electrode and the surface of STO ceramics had a great influence on the capacitance and dielectric properties of STO GBIL capacitor in reality. The experiment result shows that the capacitance and dielectric constant is small for STO ceramic capacitor when the contact of electrode/STO is non-ohmic while it becomes much larger when the contact is ohmic type. The dielectric performance of STO GBIL capacitor can reach at a best value of εr= 22 850 and tgδ = 1. 0% by adjusting the making the Ag electrode as at a temperature of T = 880 ℃ and time t = 3. 5 h by using slurry Ag material.更多还原