采用固相法制备了(0.8-x)Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3-xBaMnO3(简称NBT-KBT-BM)无铅压电陶瓷,研究了不同BM含量(x=0,0.25%,0.50%,0.75%,1.00%,1.25%,物质的量分数)样品的物相组成、显微结构及电性能。结果表明:所制备的NBT-KBT-BM陶瓷样品均为单一的钙钛矿结构。与纯NBT-KBT陶瓷相比,掺BM陶瓷的烧结温度降低,相对密度ρr得到提高。随x的增加,材料的压电常数d33、平面机电耦合系数kp与机械品质因子Qm先增大后减小,而介电损耗tanδ以及退极化温度Td一直降低。BM的掺入降低了材料的矫顽场Ec,提高了剩余极化强度Pr,从而增强了铁电性。当x=0.75%时,陶瓷获得最佳性能:d33=167 pC/N,kp=0.269,Qm=133,εr=774,tanδ=2.93%。
Lead-free piezoelectric ceramics ( 0. 8 - x ) Na0.5 Bi0.5 TiO3-0. 2K0.5 Bi0.5 TiO3-xBaMnO3 (abbreviated as NBT-KBT-BM ) were prepared by the solid state reaction. The phase composition, microstructure and electrical properties for NBT-KBT-BM samples with different BM content (x = 0, 0. 25% , 0.50% , 0.75%, 1.00% , 1.25% in mole) were investigated. It is found that all the samples exhibite a pure perovskite phase. Sintering temperature of NBT-KBT ceramics after doping BM decreases and relative density increases compared with pure NBT-KBT. The piezoelectric constant d33, electromechanical planar coupling factor kp and mechanical quality factor Qm increase first and then decrease, while dielectric constant tan6 and depolarization temperature Td decrease as the BM content increasing. BM doping could reduce the coercive field Ec and increase the strength polarization Pr, thus improving the ferroelectric properties. This system ceramics of the remanent with the bestcomprehensive properties could be obtained at x =0.75% : d33, Qm, kp, εr and tanS is 167pC/N, 0. 269, 133,774 and 2.93%, respectively.