摘要
研究了Nb2O5/Co2O3摩尔比(简称Nb/Co比,下同)对(Ba,Sr)TiO3(Barium Strontium Titanate,BST)铁电电容器陶瓷介电性能的影响,得到不同Nb/Co比与BST陶瓷性能的关系。借助扫描电镜(SEM)研究Nb/Co比对BST陶瓷微观结构的影响,采用X射线衍射(XRD)分析了BST陶瓷物相组成,探讨了Nb/Co比对BST陶瓷性能影响的机理。结果表明:当Nb/Co比为1.1,可得到满足X7R特性、介电常数为2449、耐压为5 MV/m以上综合性能好的BST陶瓷。Nb/Co比增大对BST陶瓷性能的影响是通过阻止晶粒生长、致密化、(适当增加Nb/Co比能细晶化、过量增加Nb/Co比导致少量晶粒异常长大、)宽化介电常数温度曲线、改善介电常数温度特性、减少介电常数、形成杂相、形成“晶核-晶壳”结构等进行。通过研究获得高介高压高稳定电容器陶瓷。
The influence of Nb2O5/Co2O3 mol ratio (Nb/Co) on the properties of (Ba,Sr)TiO3 (BST) capacitor ceramics were investigated ,and the relationship between the Nb/Co ratio and the properties of BST were obtained .The influence of Nb/Co ratio on the microstructure of BST ceramics were studied by scanning electron microscope and X-ray diffraction. The mechanism on modifying the properties and microstructure of the BST ceramics by doping various Nb/Co ratios was investigated. Results show that the BST ceramics with the optimal properties can be obtained when the Nb/Co ratio is 1.1, including the X7R property, a dielectric constant of 2449 and a breakdown voltage of more than 5 MV/m. The properties and microstructure of the BST ceramics were affected by Increasing the Nb/Co ratio due to the stopping of grain growth, the fining grain, the densifying, t.'.e widening the εr- θ(dielectric constant temperature) curve, the improvement of εr- θ property, the decrease of dielectric constant, the formation of other phase, and the formation of "Core-Shell" structure. As a result, the capacitor ceramics with high dielectric constant, high voltage and high stability were obtained.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2006年第A02期309-312,共4页
Rare Metal Materials and Engineering
关键词
氧化铌
氧化钴
电容器陶瓷
钛酸钡锶
陶瓷
niobium oxide
cobalt oxide
capacitor ceramics
barium strontium titanate
ceramics