掺钇铌酸锌铋陶瓷的介电性能  

DIELECTRIC PROPERTIES OF BISMUTH ZINC NIOBATE CERAMICS

作　　者：徐清华[1] 杨同青[1] 乔宏伟[1] 沈波[1] 姚熹[1] 

机构地区：[1]同济大学功能材料研究所,上海200092

出　　处：《硅酸盐学报》2007年第4期447-450,共4页Journal of The Chinese Ceramic Society

基　　金：国家"973"(2002CB613302)资助项目

摘　　要：通过X射线衍射、扫描电镜、精密阻抗分析仪等对A位Y3+取代的Bi(1.5–x)YxZnNb1.5O7介质陶瓷样品的结构和介电性能进行了研究。结果表明:当Y3+取代量较少时(x≤0.2),样品保持立方焦绿石结构;当Y3+取代较多时(x≥0.4),样品出现第二相。随着取代量的增加,样品的致密化温度升高,表观密度减小,晶粒尺寸减小,介电常数减小,介电损耗增加。Y3+取代后(x≤0.8),样品的温度系数得到优化,且具有良好的高频稳定性。低温的介电弛豫现象随着Y3+取代的增加发生有规律的变化,表现为介电常数下降,介电常数峰宽化和平坦。The structure and dielectric properties of Y^3＋ substitution in the A site of Bi1.5-xYxZNNb1.5O7 ceramic were investigated by X-ray diffraction, scanning electron microscopy and precision impedance tester. The results show that the structure of the ceramics remains a pyrochlores phase with Y3^＋ substitution ofx≤0.2 and exhibits a second phase with the Y3^＋ substitution ofx≥0.4. With the increase of the Y3^＋ substitution, the bulk density, grain size and dielectric constant decrease while the temperature for densification and dielectric loss increase. With the Y3^＋ substitution （x≤0.8）, the temperature coefficient of the dielectric constant is optimized and the samples have excellent stability as a function of frequency. The relaxation behavior in the low temperature range exhibits a regular change with Y3^＋ substitution. The dielectric constant decreases and the dielectric constant peak flattens with the increase of Y3^＋ substitution.

关 键 词：铌酸锌铋陶瓷 取代 介电性能 弛豫 

分 类 号：TM281[一般工业技术—材料科学与工程]