Structure and properties of (1−x)[(K$_{0.5}$Na$_{0.5}$)NbO$_3$–LiSbO$_3$]– xBiFe$_{0.8}$Co$_{0.2}$O$_3$ lead-free piezoelectric ceramics

Bulletin of Materials Science

关键词: Piezoelectric ceramics;    KNN–LS;    BFC-doping;    properties.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Lead-free piezoelectric ceramics $(1−x)$[0.95(K$_{0.5}$Na$_{0.5}$)NbO$_3$–0.05LiSbO$_3$]–$x$BiFe$_{0.8}$Co$_{0.2}$O$_{3}$(KNN–LS–$x$BFC) were prepared by a conventional sintering technique. The effect of BFC content on the structure, piezoelectricand electrical properties of KNN–LS ceramics was investigated. The results reveal that the BFC is effective in promoting the sinterability and the electrical properties of the ceramics sintering at low temperature of 1030$^{\circ}$C. Theceramics show a single perovskite structure, in which the tetragonal phase decreases while the orthorhombic phase increases with the increase of $x$. The more the BFC content is, the smaller and homogeneous grains were formed.With the increase of $x$, the $d_{33}$ and the $k_p$ increase to a maximum value and then slightly decrease, but the $Q_m$ increases continuously. As BFC content increases, the Curie temperature $T_c$ and remnant polarization $P_r$ decrease, but the diffusivity of phase transition in KNN–LS ceramics will intensify and the coercive field $E_c$ fluctuate between 1.16 and 1.51 kV mm$^{−1}$. The samples with $x =0.004$ exhibit optimum electrical properties at room temperature ($d_{33} = 268 pC$ N$^{−1}$, $k_p =52$%, $\epsilon_r = 1366$, $\tan \delta =2.11$%, $T_c = 325^{\circ}$C, $P_r = 20.4$ $\mu$C cm$^{−2}$, $E_c =1.16$ kV mm$^{−1}$).

【 授权许可】

CC BY