The development of high-performance BiFeO3-PbTiO3 (BF-PT) piezoelectric compositions is highly desirable, but still challenged due to their high Curie temperature (Tc), large lattice distortion and octahedral tilt induced large antiferrodistortion in rhombohedral-tetragonal phase (R3c-P4 mm) coexisted compositions. Here, a dual strategy by introducing the pseudo-cubic (Pc) phase in place of the R3c phase, and adjusting the lattice distortion of P4 mm phase was realized in 0.60Bi0.95La0.05FeO3-(0.40-x)PbTiO3-xBaTiO3, where a large piezoelectric coefficient d33 of ∼410 pC/N, a high Tc of ∼416 °C as well as a good thermal stability can be achieved at x = 0.20 composition. The structural analyses indicate that the superior piezoelectric activity should be associated with several factors including the coexistence of tetragonal (T) and Pc phases without octahedral tilt, the field-induced reversible T-Pc transition and the optimized c/a ratio. More pronouncedly, the extrinsic piezoelectric response induced by significantly enhanced domain wall motion contributes to almost ∼70 % of the quasi-static d33 value. Moreover, the robust domain texture up to ∼400 °C is responsible for its good thermal stability. These merits suggest giant potentials of the elaborately-designed composition as high-temperature piezoelectric materials.

中文翻译：

---

通过刷新相边界精心设计的高性能 BiFeO3-PbTiO3 陶瓷


高性能 BiFeO3-PbTiO3 （BF-PT） 压电成分的开发是非常可取的，但由于其高居里温度 （Tc）、大晶格畸变和八面体倾斜在菱面体-四方相 （R3c-P4 mm） 共存成分中诱导的大反铁畸变，仍然存在挑战。在此，在 0.60Bi0.95La0.05FeO3-（0.40-x）PbTiO3-xBaTiO3 中，通过引入伪立方 （Pc） 相代替 R3c 相并调整 P4 mm 相的晶格畸变，实现了双重策略，其中在 x = 0.20 成分下可以实现 ∼410 pC/N 的大压电系数 d33、∼416 °C 的高 Tc 以及良好的热稳定性。结构分析表明，优异的压电活性应与几个因素有关，包括无八面体倾斜的四方 （T） 和 Pc 相共存、场诱导可逆 T-Pc 跃迁和优化的 c/a 比。更明显的是，由显著增强的畴壁运动引起的外源压电响应贡献了准静态 d33 值的近 70%。此外，高达 ∼400 °C 的坚固畴织构是其良好的热稳定性的原因。这些优点表明，精心设计的成分作为高温压电材料具有巨大的潜力。