WEI Wei ,JIANG Xiangping ,CHEN Chao ,TU Na, LI Xiaohong

(Jiangxi Key Laboratory of Advanced Ceramic Materials, School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen Jiangxi 333403，China)

Abstract: Lead-free (1-x) Li_0.04Na_0.52K_0.44Nb_0.86Ta_0.10Sb_0.04O₃-xBaCu_0.5W_0.5O₃ [(1 -x)LF4-xBCW] piezoelectric ceramics have been fabricated by the traditional solid state reaction. The microstructure and electrical properties of LF4 ceramics with different BCW content (x = 0%, 0.1%, 0.25%, 0.5%, 1%, in mole) are investigated. The results show that KNN ceramics still have the perovskite structure after being doped with BCW. The structure of samples has changed from tetragonal to orthorhombic when x≥1%, T_{o -t} can be detected, and Tc shifts to lower temperature. The modification of BCW doping hardened this material with lower k_p, tanδ, d₃₃ and remarkably higher Q_m than pure LF4 ceramics. Furthermore, the sintering temperature of LF4 ceramics decreases and the density increases evidently with the increase of BCW content.

Keywords: modification, Li_0.04Na_0.52K_0.44Nb_0.86Ta_0.10Sb_0.04O₃,lead-free piezoelectric ceramics