Superior piezoelectricity in lead-free barium titanate piezoceramics

Since the 21st century, increasing environmental protection and human health concern have been the driving force to develop lead-free piezoelectric materials with enhanced performances, and phase engineering strategy has been validated to be a viable method in numerous methodologies. Here, we gained a superb d(33)similar to(637 +/- 30) pC/N in lead-free (1-x)(Ba0.93Ca0.07)(Sn0.08Ti0.92)O-3-x(Sb0.5Li0.5)TiO3 [abbreviated as (1-x)BCST-xSLT, 0 <= x <= 0.4% (in mole)] piezoelectrics utilizing chemical doping. To illustrate the relationship among composition-structure-performance, microstructure characterization, electrical properties measurement, first-principles calculation, and phase-field simulations were performed. Atomic-resolved polarization mapping of z-contrast imaging manifests the ferroelectric three phases (RO-T) coexist at the nanoscale with nanoscale polarization switching among them. Theoretical calculations and simulations confirm that the high-density nano-domain boundary bridges the polyphase coexisting nano-domains, which makes the polarization reversal easy, thus significantly reducing the energy barrier and polarization anisotropy among different phases. (c) 2023 The Authors. Published by Elsevier B.V. on behalf of The Chinese Ceramic Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).