钙钛矿型低铅压电陶瓷的制备与性能研究

摘要

xPbTi0.4716Zr0. 4834 （Mn1/3 Sb2/3 ）0. 0450O3- （ 1 - x） （K0. 485Na0. 485 Li0. 03 ） NbO3 [xPMS- （ 1 -x） KNLN] ceramics with low-lead component were prepared by using conventional ceramics method. Microstructure, piezoelectric and ferroelectric properties of the low-lead ceramics with different stoichiometry x fabricated at varied sintering temperature were studied. The XRD patterns of the ceramics show that the microstructure of the ceramics transform from a coexistence state of pyroehlore and pseudo-cubic perovskite to tetragonal perovskite while sin- tering temperature increases. The SEM analysis shows that a liquid-phase formed by the （K0.485 Na0.485, Li0.05 ） NbO3 component appeared during the sintering process and while the sintering temperature increases the holes appeared on the surface of the ceramics and disappeared when the ceramics were sintered at even higher sintering temperature. The electric measurement results obtained show that xPMS-（1-x）KNLN ceramics possess good piezoelectric and ferroelectric properties, and when sintered at 1250℃, the xPMS-（1-x）KNLN ceramics with x=0.75 ceramic possess the properties of daa = 182pC/N, kp = 34. 5%, Tc = 165 ℃, Pr = 21.2μC/cme, Ec = 1.47kV/mm, εr=1879 and tanδ=0.92%.%采用传统陶瓷工艺制备了钙钛矿型低铅压电陶瓷xPbTi0.4716Zr0.4834（Mn1/3Sb2/3）0.0450O3-（1-x）（K0.485Na0.485Li0.03）NbO3[xPMS-（1-x）KNLN],研究了该陶瓷体系的结构和介电、压电与铁电性能以及这些结构和性能与工艺条件的关系。XRD分析表明,随着烧结温度的升高,陶瓷晶相由焦绿石相与赝立方钙钛矿相共存转变为单一的四方钙钛矿相;SEM分析表明,在烧结过程中产生了以（K0.485Na0.485Li0.03）NbO3组分为主的液相,并在烧结温度提高的过程中产生孔洞出现-孔洞消失的现象;电学测试表明,xPMS-（1-x）KNLN陶瓷具有良好的性能,在x=0.75、烧结温度为1250℃时,陶瓷的性能参数为压电常数d33=182pC/N,机电耦合系数kp=34.5%,居里温度TC=165℃,剩余极化强度Pr=21.2μC/cm2,矫顽场强Ec=1.47kV/mm,介电常数εr=1879,介电损耗tanδ=0.92%。