Simultaneously Achieved High Piezoelectricity and High Resistivity in Na0.5Bi4.5Ti4O15-Based Ceramics with High Curie Temperature

Good piezoelectricity and high resistivity are prerequisites for high-temperature acceleration sensors to function correctly in high-temperature environments. Bismuth layered structure ferroelectrics (BLSFs) are promising candidates for piezoelectric ceramics with excellent piezoelectric performance at high temperatures, high electrical resistivity, and high Curie temperatures (Tc). In this study, (LiMn)5+ is substituted for Bi at the A-site, and Ce-doping is performed to replace Ti ions in Na0.5Bi4.5Ti4O15, which achieves the desired combination of high piezoelectric coefficients and high resistivity. Herein, we prepared Na0.5Bi3(LiMn)0.9Ti4−xCexO15 high-temperature piezoelectric ceramics, achieving a high piezoelectric coefficient d33 of 32.0 pC/N and a high resistivity ρ of 1.2 × 108 Ω·cm (at 500 °C), and a high Curie temperature of 648 °C. It is important that the d33 variation remains within 8% over a wide temperature range from 25 °C to 600 °C, demonstrating excellent thermal stability. Structural characterization and microstructure analysis showed that the excellent piezoelectric coefficient and high resistivity of cerium-doped Na0.5Bi4.5Ti4O15-based ceramics are attributable to the synergistic effects of structural characteristics, defect concentration, refined grain size and domain morphology. This study demonstrates that the superior properties of Na0.5Bi3(LiMn)0.9Ti4−xCexO15 ceramics are crucial for the stable operation of high-temperature accelerometer sensors and for the development of high-temperature devices.