It is a very difficult work to sinter K_0.5Na_0.5NbO₃ (KNN)-based materials with good reduction resistance in strong reducing atmosphere. 0.945K_0.48Na_0.52Nb_0.96Ta_0.04O₃−0.055BaZrO₃ + 0.03ZrO₂ + y mol%MnO (KNNT−0.055BZ + 0.03Zr + yMn) ceramics sintered in reducing atmosphere were prepared successfully by conventional solid-state reaction methods. MnO dopant increases grain size at y = 5–8 due to strong lattice distortion and then decreases grain size at y = 9 due to much Mn₄Nb₂O₉ accumulated at the grain boundary. MnO dopant as an excellent sintering aid can effectively reduce volatilization of alkali metal by decreasing the sintering temperature (T_sinter). Reducing alkali metal volatilization can greatly reduce oxygen vacancies and improve piezoelectric properties. MnO dopant can improve the anti-reduction properties. The KNNT−0.055BZ + 0.03Zr + yMn ceramics at y = 6–9 show outstanding anti-fatigue of unipolar piezoelectric strain under the synergistic effect of reduced oxygen vacancies due to reduced volatilization and increased grain size. Piezoelectric properties and temperature stability of KNNT−0.055BZ + 0.03Zr ceramics sintered in reducing atmosphere are improved simultaneously by MnO dopant. Optimum inverse piezoelectric coefficient (d ^*₃₃ ) of ceramics at y = 8 reaches up to 480 pm/V under low driving electric field E = 20 kV/cm at room temperature, and its temperature stability of d ^*₃₃ reaches 158 °C. It will be an excellent lead-free material candidate for the preparation of multilayer piezoelectric actuators co-fired with nickel electrode.

在强还原气氛中烧结具有良好抗还原性的K _0.5 Na _0.5 NbO ₃ (KNN)基材料是一项非常困难的工作。0.945K _0.48 Na _0.52 Nb _0.96 Ta _0.04 O ₃ -0.055BaZrO ₃ + 0.03ZrO ₂ + y mol%MnO (KNNT-0.055BZ + 0.03Zr + y Mn) 在常规还原气氛中通过还原反应成功制备陶瓷方法。由于强烈的晶格畸变，MnO 掺杂剂在y = 5–8处增加晶粒尺寸，然后由于大量 Mn 而在y = 9处减小晶粒尺寸₄ Nb ₂ O ₉积累在晶界处。掺杂剂的MnO作为优异的烧结助剂可以通过降低烧结温度（有效地降低碱金属的挥发Ť_烧结）。减少碱金属挥发可以大大减少氧空位，提高压电性能。MnO掺杂可以提高抗还原性能。KNNT−0.055BZ + 0.03Zr + y Mn 陶瓷在y= 6-9 表明在由于减少的挥发和增加的晶粒尺寸而减少的氧空位的协同作用下，单极压电应变具有出色的抗疲劳性。MnO掺杂同时提高了在还原气氛下烧结的KNNT-0.055BZ + 0.03Zr陶瓷的压电性能和温度稳定性。室温低驱动电场E = 20 kV/cm下，陶瓷在y = 8处的最佳逆压电系数( d ^* ₃₃ )可达480 pm/V ，温度稳定性d ^* ₃₃ 达到 158°C。它将是制备与镍电极共烧的多层压电致动器的极好无铅材料候选者。