Giant piezoelectricity and ultrahigh strain response in bismuth sodium titanate lead-free ceramics

• The BNBT-x SZMO with appropriated SZMO exhibited optimum electrical properties.
• It has a relatively high strain S of 0.388%.
• It exhibits high Smax/Emax=597 pm/V and large d33=141 pC/N at x=0.005.
• Modified sample has great potential for actuator and multifunctional device applications.

The obvious conflicts between large piezoelectricity and high strain could be solved by adding new components in BNT. Moreover, this urgent problem has been solved and induced a large strain as well as a high piezoelectricity in BNT. Large normalized strain (d33*=526–597 pm/V) and high strain (0.342%–0.388%) were achieved at the composition range of 0.0025≤x≤0.0050, suggesting that such a system is a promising lead-free candidate for electromechanical actuator applications. Furthermore, high d33 values of 141–204 pC/N have also been attained at the above composition range due to adding new components.