| Abstract Scope |
Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> (BNT) is an important lead-free ferroelectric ceramic material. Due to their unique crystal structure, BNT-based ceramics usually have high remanent polarization, large coercive field and relaxor characteristics. Therefore, they can be promising candidates for piezoelectric actuators, dielectric energy storage capacitors, oxygen ion conductors, and etc. Recently, we made a series of modifications to the BNT ceramic material, and the structure and relaxor properties of the modified ceramics were analyzed thoroughly. An ultrahigh energy storage density (~4.77 J/cm<sup>3</sup>) and good stability of performance were achieved in the Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub>-CaZr<sub>0.5</sub>Ti<sub>0.5</sub>O<sub>3</sub> ceramics, possessing a fast discharge speed and high power density. In addition, a giant electro-strain (~2%) under high temperature was obtained in the relaxor BNT-based ceramics and the related mechanism was further demonstrated. This work is beneficial to expand the versatility of BNT-based materials and provide useful ideas to design high-performance lead-free ferroelectric and piezoelectric ceramics. |