LiSbO3掺杂NBT-KBT无铅压电陶瓷的研究

Studies on (Na_(0.5)Bi_(0.5))TiO_3(K_(0.5)Bi_(0.5))TiO_3 Lead-free Piezoelectric Ceramics Modified by Doping-LiSbO_3

采用固相法制备了LiSbO3掺杂0.8(Na0.5Bi0.5)TiO3-0.2(K0.5Bi0.5)TiO3(简称NBT-KBT-LS)无铅压电陶瓷,研究了LS的不同摩尔分数掺杂(0≤x≤1.50%)对样品的显微结构及电性能的影响。结果表明,所制备的NBT-KBT-LS陶瓷样品均为单一的钙钛矿结构,LS的掺入促进了晶粒的长大,但由于Bi 3+与Na+的挥发,导致块状晶粒的出现。掺杂一定量的LS,陶瓷的压电常数d33、机电耦合系数kp、机械品质因子Qm、剩余极化强度Pr与矫顽场Ec均增大,表现出"软硬双性"的掺杂作用。当x=0.75%时,材料的性能最佳:d33=154pC/N,kp=0.268,Qm=107。

LiSbOa-modified 0.8（Na0.5Bi0.5）TiO3-0.2（K0.5Bi0.5）TiO3（ abbreviated as NBT-KBT-LS） lead-free piezoelectric ceramics were prepared by the solid state reaction method. The effect of LS content （0≤x≤50%） on the microstructure and electrical properties of the ceramics were studied carefully. It was found that all the NBT- KBT-LS samples exhibited a pure perovskite phase. The grain size of those materials increased after doping LS. Some large and plate-like second phase appeared in such ceramic systems because some Bia＋ and Na＋ volatilize due to the overheating at high temperature. The piezoelectric constant daa , eleetromechanical planar coupling factor kp ,me- chanical quality factor Qm, the remanent polarization Pr, the coercive field Ec were increased by doping appropriate amount of LS. It showed that the dopant of LS had ＂soft and hard double properties＂ dopant effect. The optimum electric properties （d33 =154 pC/N,kp=0. 268,Qm=107） could be found in the composition of x=0. 750/oo.