铋含量对钛酸镧铋陶瓷结构和介电性能的影响(英文)

Influence of Bi Content on the Structure and Dielectric Properties of Lanthanum-modified Bismuth Titanate Ceramics by the Conventional Solid-solution Technique

通过固相合成的方法制备了Bi3.25-xLaxTi3O12(x=0.98～1.03,简称BLT)陶瓷。通过XRD,SEM和阻抗分析仪表征了陶瓷的晶体结构和晶体形貌,测试了陶瓷的介电频谱,结果表明陶瓷的晶体结构为典型的层状钙钛矿结构且不随Bi含量和温度的变化而改变;随着Bi含量的增加晶体形貌由棒状颗粒向片状颗粒转变,而且陶瓷的致密度也得到提高;介电常数随Bi含量的增加先增大后减小,并且在x=1.02时达到最大值。

Lanthanum-modified bismuth titanate, Bi3.25-x La0.75 Ti3O12 （BLT） ceramics, with x ranging from 0.98 to 1.03 were prepared by the conventional solid-solution technique. The crystal structure, morphological and dielectric properties of BLT ceramics were investigated by the X-ray diffraction （XRD）, the scanning electron microscopy （SEM） and the impendence analyzer. It is indicated that the crystal structure of ceramic is a classic Bi-layer perovskite structure. The crystal structure doesn＇t change with bismuth content and the sintering temperature. The micro morphology transformes from stick-like crystal grains to slice-like crystal grains with bismuth content increasing. The dielectric constant firstly increases then decreases with increasing content of bismuth, and arrives at a maximum at x = 1.02.