CBS掺杂对钛酸钡陶瓷介电性能的影响

研究了钙硼硅(CBS)微晶玻璃掺杂BaTiO3(BT)-Nb2O5-ZnO系统的微结构和介电性能,并用掺杂后晶粒壳与晶粒芯体积分数的变化规律分析了其改性机理。对比SEM照片得出,不同含量CBS掺杂BT的室温εr与掺杂后BT陶瓷的晶粒生长情况以及玻璃相的多少和分布密切相关。经优化配方和工艺后,在空气中于1150℃烧成的BaTiO3陶瓷材料的主要性能指标达到:εr25℃>1350,tgδ≤1.0×10-2,ρ≥1011?·cm,最大电容量变化率不超过±10%(-55～+150℃),适于制备中温烧结X8R多层陶瓷电容器。

Influence of CBS Doping on Dielectric Properties of BaTiO3 Ceramics

Investigated were the microstructure and dielectric properties of BaTiO3(BT)-Nb2O5-ZnO system doped with CBS glass-ceramic.The results reveal that when the amount of CBS is small,it assembles at grain boundary.And the barium titanate grains are coated with glass as the amount of CBS increases.The various effects of different amount of CBS doping on the BT ceramics can be explained by the volume proportion change of grain core and grain shell in the core-shell structure.After the SEM photographs were analyzed,it proves that εr has close relationship with the grain size of BT ceramics and the volume proportion and distribution of the glass phase.By optimizing composition and technical process,the BaTiO3 ceramics sintered at 1 150℃ into the atmosphere have perfect dielectric properties:εr 25℃>1 300,tgδ≤1.0×10-2,ρ≥1011?·cm,ΔC/C≤ ±10%(-55~+155℃).This material is promising for the preparation of X8R MLCC.