摘要
采用固相法制备了Bi补偿的(0.84-x)Na0.5Bi0.5TiO3-0.16K0.5Bi0.5TiO3-x SrTiO3(简称NBTKBT-xST)无铅压电陶瓷,研究不同ST掺量对体系陶瓷的结构与电性能的影响规律。结果表明,在掺杂范围内(0≤x≤0.06),材料均能形成单一的钙钛矿固溶体结构。随着x的增加,陶瓷晶体结构逐渐由三方相向四方相过渡,且该体系的三方-四方准同型相界(MPB)位于0.03≤x≤0.04。在此组成区域内,体系陶瓷的铁电与压电性能较好,其中x=0.04时,材料的电性能较好:压电常数d33=156 pC/N,平面机电耦合系数k p=0.29,相对介电常数εr=1116,介质损耗tanδ=4.1%,剩余极化强度P r=30.5μC/cm2,矫顽场E c=23.9 kV/cm。介电温谱和变温电滞回线表明体系陶瓷在T d以上可能存在极性相与非极性相共存。
Bi-compensated （0.8-x）Na0.5Bi0.5TIO3-0.16K0.5Bi0.5TiO3-xSrTiO3 （abbreviated as NBT-KBT-xST） lead-free piezoelectric ceramics were prepared by solid-state reactions. The effects of SrTiO3 dopants on the structure and electrical properties of ceramic samples were investigated. The results indicated that solid so lutions with pure perovskite structure were formed after SrTiO3-doping. The phase structures of the ceramics at room temperature changed from rhombohedral to tetragonal phases as increasing the SrTiO3 contents, and a morphotropic phase boundary （MPB） of the system was found to be 0.03 ≤x≤0.04, where good ferroelectric and piezoelectric properties were obtained. When x = 0.04, the ceramics exhibit the best physical performance： the piezoelectric constant d33 = 156 pC/N, planar coupling factor kp = 0. 29, relative dielectric constant εr=1 116, dielectric loss tanδ= 4.1 %, remnant polarization Pr ： 30. 5 μC/cm2 , coercive field Er=23.9 kV/cm. The temperature dependences of dielectric and ferroelectric properties indicate that the ceramics may contain both the polar and non-polar regions at temperatures above the de-polarized temperature （Td）.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2014年第4期90-94,共5页
Journal of Functional Materials
基金
国家自然科学基金资助项目(51062005
91022027)
关键词
钙钛矿
无铅压电陶瓷
准同型相界
电性能
perovskite
lead-free piezoelectric ceramics
morphotropic phase boundary
electrical properties
