Simultaneously Achieved High Piezoelectricity and High Resistivity in Na_0.5Bi_4.5Ti₄O₁₅-Based Ceramics with High Curie...

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 (T_c). In this study, (LiMn)⁵⁺ is substituted for Bi at the A-site, and Ce-doping is performed to replace Ti ions in Na_0.5Bi_4.5Ti₄O₁₅, which achieves the desired combination of high piezoelectric coefficients and high resistivity. Herein, we prepared Na_0.5Bi₃(LiMn)_0.9Ti_4-xCe_xO₁₅ 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 Na_0.5Bi_4.5Ti₄O₁₅-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 Na_0.5Bi₃(LiMn)_0.9Ti_4-xCe_xO₁₅ ceramics are crucial for the stable operation of high-temperature accelerometer sensors and for the development of high-temperature devices.