BNT-BKT-BiFeO_3无铅压电陶瓷的压电性能和退极化温度  

Piezoelectric Properties and Depolarization Temperature of Lead-free Piezoelectric Ceramics of BNT-BKT-BiFeO_3

作　　者：杨桂华[1] 周昌荣[2] 

机构地区：[1]桂林工学院电子与计算机系,桂林541004 [2]桂林电子科技大学信息材料科学与工程系,桂林541004

出　　处：《人工晶体学报》2009年第2期335-339,共5页Journal of Synthetic Crystals

基　　金：广西自然科学基金(No.0447092);广西信息材料重点实验室主任基金

摘　　要：采用传统陶瓷制备方法,制备了系列新型无铅压电陶瓷材料(1-x-y)Bi0.5Na0.5TiO3-xBi0.5K0.5TiO3-yBiFeO3(简写为BNT-BKT-BF-x/y)。研究了该体系陶瓷微观结构、压电性能和退极化温度变化规律。结果表明:在所研究的组成范围内,所制备的材料均能够形成纯钙钛矿固溶体,陶瓷三方、四方共存的准同型相界(MPB)成分为x=0.18～0.21,y=0～0.05,在准同型相界成分附近该体系陶瓷压电性能达到最大值:d33=171pC/N,kp=0.366。采用平面机电耦合系数kp和极化相位角θmax与温度的关系来确定退极化温度,得到的结果基本相同,陶瓷的退极化温度随BF含量的增加一直降低,随BKT含量的增加先降低后升高。The series of （Bi0.5Na0.5）TiO3-based lead-free piezoelectric ceramic, （1-x-y）Bi0.5Na0.5TiO3-xBi0.5K0.5TiO3-yBiFeO3（BNT-BKT-BF-x/y） lead-free piezoelectric ceramic were prepared by a conventional ceramic sintering method. The crystal structure, and piezoelectric properties and depolarization temperature of the ceramics were investigated. The results indicate that the ceramics studied can form pure perovskite structure solutions. The morphotropic phase boundary（MPB） of the system between rhombohedral and tetragonal locates in the range of x=0.18- 0.21 and y=0- 0.05. The optimum piezoelectric properties were obtained near the MPB composition, and the piezoelectric constant d33 and the electromechanical coupling factor kp of the ceramics attain maximum values of 171 pC/N and 0.366 at x=0.18 and y=0.03. The depolarization temperatures confirmed by kp and θmax were almost identify. The depolarization temperature keeps decreasing as the BF content increaing, and first decreases and then increases with an increasing content of BKT.

关 键 词：退极化温度 无铅压电陶瓷 钙钛矿结构 准同型相界 

分 类 号：TM282[一般工业技术—材料科学与工程]