Synergistic Design Strategy for Enhancing the Piezoelectric Performance of BiFeO3-Based High-Temperature Piezoelectric Ceramics

A novel synergistic strategy was used to improve the piezoelectric characteristics of high-temperature piezoelectric ceramics. This work combined three commonly used strategies, constructing the Morphotropic Phase Boundary to reduce energy barriers, changing domain structures impacting macroscopic piezoelectric properties, and adjusting BO6 octahedral distortions reflecting microstructural changes, thus effectively regulating the piezoelectric behaviors of BiFeO3-based ceramics. As a result, the 0.67BiFeO3-0.32BaTiO3-0.01BiAlO3 component, exhibiting the maximum distortion of the BO6 octahedron and the coexistence of macrodomains and nanodomains, achieved the optimal piezoelectric characteristics (d33 = 225±10 pC N-1, TC = 450 °C). Additionally, the ceramic maintained its high piezoelectric properties even at temperatures as high as 280°C (346 pC N-1). This study presents a novel collaborative design strategy that combines phase structure, domain structure, and BO6 octahedral distortion, significantly enhancing the development potential of lead-free high-temperature piezoelectric materials in the future.