Large piezoelectric strain under a low driving electric field in Sm3+-doped BaTiO3 lead-free piezoelectric ceramics

Abstract

Lead-free (Ba_1−xSm_x)(Sn_0.08Ti_0.92)O₃–0.6%MnO₂ ceramics with an outstanding piezoelectric strain coefficient of 1580 pm V⁻¹ are successfully prepared under a very low driving electric field E_D of 3 kV cm⁻¹. Our design strategy involved constructing unique microstructures with atomic-scale polar nanoregions (PNRs) embedded in nano-domains, which is achieved by the introduction of 0.2% Sm³⁺ ions with a small ionic radius into the A-site of the BT perovskite structure. The atomic-scale PNRs induced by point defects embedded in nano-domains flatten the Landau energy profile, increasing the piezoelectric strain and decreasing the E_D. This provides a new doping strategy for exploring lead-free piezoelectric ceramics as alternatives to lead-based piezoelectric ceramics. We believe that this is an important step for the development of lead-free ceramics in the future.