Effect of BaTiO3 particles with different shape on electrical properties of (Bi0.5Na0.5)TiO3 piezoceramics

Abstract

Lead-free (Bi0.5Na0.5)TiO3-based materials are becoming a viable alternative to lead-based material in developing piezoelectricity strategies, due to its high piezoelectric performance as well as large strain response. In the present work, three kind of micro-sized, nano-sized, and plate-like BaTiO3 particles were employed to tailor the electrical properties of (Bi0.5Na0.5)TiO3 piezoceramics. The piezoelectric, strain properties, and phase transition temperature could be improved when employing BT nano-sized particles instead of BT micro-sized and plate-like particles as the raw material. Besides, addition of BT nano-sized particles could also yield a decreased critical poling filed of 22 kV/cm, compared with BT micro-sized (24 kV/cm) and plate-like (28 kV/cm) particles. Most intriguingly, an enhanced frequency-dependent unipolar strain in relative to other lead-free ceramics was also realized in the ceramics with BT nano-sized particles. In addition, the fatigue response of plate-like BT particles-modified ceramics was superior to that of nano- and micro-sized ones, which was mainly attributed to the lower defect density. This study demonstrates the superiority of uniform and nano-scale modifier for BNT-based ceramics, and also provides new opportunities to tailor and control piezoelectric activity for actuator applications.