Abstract (Bi0.5Na0.5)TiO3–BaTiO3 lead-free piezoelectric ceramics exhibit excellent piezoelectric properties, but its piezoelectric property with high thermal stability is the major obstacle limiting the potential application. In this study, the KNbO3 (KN) was adopted to 0.875(Bi0.5Na0.5)TiO3-0.125BaTiO3 (BNT-12.5BT) by conventional solid-state reaction to enhance the piezoelectric properties in high temperature. The results of X-ray diffraction (XRD) indicate that KN has diffused into BNT-12.5BT lattices to form a pure perovskite structure and not exert a severe disturbance on the ferroelectric tetragonal lattice. The depolarization temperature Td is maintained at a high level. For piezoelectric properties, at KN modification x = 0.01, the piezoelectric coefficient (d33) increases to 147 pC/N from 135 pC/N for unmodified composition. Meanwhile, the d33 will increase to 187 pC/N until the depolarization temperature (185 °C) arrives, showing the excellent temperature stability of the piezoelectric properties to meet the actual demand.

中文翻译：

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(Bi0.5Na0.5)TiO3 基无铅压电陶瓷在 150 °C 以上的高压特性

摘要 (Bi0.5Na0.5)TiO3-BaTiO3无铅压电陶瓷具有优异的压电性能，但其压电性能和高热稳定性是限制其潜在应用的主要障碍。在本研究中，KNbO3 (KN) 通过常规固相反应被用于 0.875(Bi0.5Na0.5)TiO3-0.125BaTiO3 (BNT-12.5BT) 以提高高温压电性能。X射线衍射（XRD）结果表明，KN已扩散到BNT-12.5BT晶格中，形成纯钙钛矿结构，并未对铁电四方晶格产生严重干扰。去极化温度Td保持在高水平。对于压电特性，在 KN 修改 x = 0.01 时，压电系数 (d33) 从未修改组合物的 135 pC/N 增加到 147 pC/N。同时，