Bi1/2(Na1-xLix)1/2TiO3压电陶瓷的性能和微结构

利用传统陶瓷工艺制备了Bi1/2(Na1-xLix)1/2TiO3(简写BNLT100x,其中x为摩尔含量)系无铅压电陶瓷,研究了该陶瓷的微结构、压电和介电性能。X-射线衍射分析(XRD)结果表明,在x=0~0.20时,Bi1/2(Na1-xLix)1/2TiO3陶瓷为单相三方晶系钙钛矿结构;在x=0.30时,会有影响压电性能的第二相产生。扫描电镜(SEM)结果表明,Li含量越高,陶瓷的烧结温度越低,Li促进了晶粒特定方向的生长;在x=0.15时,压电系数d33达极大值109 pC/N;同时研究了极化工艺条件对材料压电性能的影响。

Piezoelectric Properties and Microstructure of Bi1/2(Na1-xLix)1/2TiO3 Piezoelectric Ceramics

Lead-free piezoelectric ceramics Bi1/2(Na1-xLix)1/2TiO3 were prepared by the conventional ceramic sintering technique.The piezoelectric properties,dielectric properties and microstructures of these piezoelectric ceramics were also studied.From the result of XRD,it was found that Bi1/2(Na1-xLix)1/2TiO3 ceramics show a single phase of perovskite structure with a rhombohedral symmetry in the range of x=0~0.20.The second phase which decreases piezoelectric properties of ceramics was found at x=0.30.From the result of SEM,the sintering temperature decreases with the increasing amounts of Li,and Li promotes the growth in some directions of crystalline grains.The measurement results of piezoelectric properties reveal that d33 reaches a maximum 109 pC/N at x=0.15.The effects of poling technique on the piezoelectric properties in the system were also investigated.