Grain-orientated lead-free BNT-based piezoceramics with giant electrostrictive effect

In this study, we propose an effective approach to gain prominent electrostrictive behavior by taking advantage of texture construction in lead-free (Bi0.5Na0.5)TiO3(BNT)-based piezoceramics for actuator applications. The electrostrictive effect was explored systematically in <00 l> textured 0.90(0.83Bi0.5Na0.5TiO3-0.17Bi0.5K0.5TiO3)-0.10NaNbO3(BNT-BKT-NN) ceramics with respect to grain orientation, temperature and electric fields. It was found that the electrostrctive coefficient Q33 and recoverable strain increase monotonously with the grain orientation increasing. At the optimized microstructure (F00 l=92%), a giant Q33 with nearly purely electrostrictive characteristics was detected to be around ~0.0354 m4C−2, which was far larger than the reported values of Pb(Mg1/3Nb2/3)O3 (PMN) and the existing BNT-based electrostrictive materials. Meanwhile, the acquired Q33 was found to exhibit excellent stability for the highly textured sample under different temperature or electric field conditions. Our achievement demonstrates that the giant electrostrictive properties with superior temperature and electric field stability for <00 l> textured BNT-BKT-NN ceramic are of great significance in replacing traditional PMN ceramics for actuator applications.