高锂含量碱金属铌酸盐的结构与性能研究

Study on the Structure and Piezoelectric Properties of High Lithium Niobate Piezoelectric Ceramics

采用传统固相法陶瓷制备工艺制得高锂铌酸基无铅压电陶瓷体系xLiNbO3-（1-x）（Na0.5K0.5）NbO3（简写为xLN-（1-x）NKN，其中x=0．146，0．236，0．292，0．348，0．361，0．382，0．438，0．472，0．500，0．528，0．618），研究了该体系的晶相结构，断面形貌及电学性能随x的变化。研究表明，随x的增加，样品主晶相有一个四方钙钛矿到四方钨青铜结构再到LiNbO3三方结构的过程；压电常数d33随着x的增加而减小，但在x=0．236～0．438时保持相对稳定，约为75～80pC／N；当x=0．5时，居里温度Tc为537℃，此系列陶瓷适用于高温环境的压电陶瓷。

High lithium niobate lead-free piezoelectric ceramics, xLiNbO3-（1 x） （Na0.5K0.5 ） NbO3 （abbreviated as xLN-（1-x）NKN, x=0. 146, 0. 236, 0. 292, 0. 348, 0. 361, 0. 382, 0. 438, 0. 472, 0. 500, 0. 528, 0. 618） system, were fabricated by conventional ceramics sintering technique. The crystal phases, surface appearance and the electric properties were studied with the various of x. The results indicated that the main phase of the sample had a process of tetragonal perovskite phase to tetragonal tungsten bronze phase and then to a LiNhO3 Rhomhohedral phase with the increase of x. Meanwhile, the piezoelectric constant declined but it remained in a range of 75～80 pC/N between 0. 236 and 0. 438 of x. When x=0.5, Tc = 537 ℃. The series of ceramics could be considered as a good candidate piezoelectric ceramics used in high-temperature environment.