(Bi_1/2Na_1/2)TiO₃-based materials have received much attention due to large electro-strain and high piezoelectric constant (d₃₃), but the tough issue is that the existence of inherent depolarization temperature (T_d) limits the temperature stability and application temperature range. Previously, reports about the formation of BNT/oxide (i.e., ZnO, Al₂O₃) composites thought that T_d can be deferred to a higher temperature and then thermal depolarization improves. However, the deferred T_d of BNT/oxide composites is limited, accompanied by a low d₃₃. Here, we design the {[Bi_0.5(Na_0.8K_0.2)_0.5]_1-xPb_x}TiO₃ ceramics, leading to a big shift of T_d from 77 ℃ to 390 ℃. Large d₃₃ (140 pC/N) and high T_d (∼263 ℃) can be simultaneously achieved for the sample with Pb=0.05, and T_d could be further deferred higher (390 ℃) for Pb=0.20. The off-centre displacement of Pb induced by Pb-O hybridization in the PbO₁₂ polyhedron and ferroelectric order stabilized by the addition of Pb can provide the driving force to strengthen the ferroelectric order, and then promote the thermal stability.

（Bi _1/2 Na _1/2）TiO ₃基材料由于其大的电应变和较高的压电常数（d ₃₃）而备受关注，但难题是固有的去极化温度（T _d）的存在。限制了温度稳定性和应用温度范围。以前，有关BNT /氧化物（即ZnO，Al ₂ O ₃）复合物形成的报道认为，可以将T _d推迟到更高的温度，然后改善热去极化。但是，BNT /氧化物复合材料的递延T _d有限，伴随着较低的d₃₃。在这里，我们设计了{[Bi _0.5（Na _0.8 K _0.2）_0.5 ] _{1- x} Pb _x } TiO ₃陶瓷，从而使T _d从77℃到390℃发生了很大的变化。对于Pb = 0.05的样品，可以同时实现大d ₃₃（140 pC / N）和高T _d（〜263℃），而当Pb = 0.20时，T _d可以进一步推迟至更高（390℃）。PbO _12中Pb-O杂交引起的Pb偏心位移 通过添加Pb可以稳定多面体和铁电有序，可以提供驱动力来增强铁电有序，进而促进热稳定性。