Lead‐free MnO‐doped 0.955K_0.5Na_0.5NbO₃‐0.045Bi_0.5Na_0.5ZrO₃ (Abbreviated as KNN‐0.045BNZ) ceramics have been prepared by the conventional solid‐state sintering method in reducing atmosphere ( = 1 × 10⁻¹⁰ atm) and air. For ceramics sintered in reducing atmosphere, only Mn²⁺ ions exist in ceramics who preferentially occupy the cation vacancies in A‐site at x = 0.2‐0.4, whereas Mn²⁺ ions substitute for Zr⁴⁺ ions in B‐site to form defects () at x > 0.4. For ceramics sintered in air, mixed Mn²⁺, Mn³⁺, and Mn⁴⁺ ions coexist here. The Mn²⁺ ions preferentially occupy the cation vacancies in A‐site at x = 0.2‐0.4 and then Mn²⁺ ions substitute for Zr⁴⁺ ions in B‐site at x > 0.4. Meanwhile, the Mn³⁺ ions and Mn⁴⁺ ions substitute for Nb⁵⁺ ions in B‐site to form defects () at x = 0.2‐0.8. The (, , and ) dipolar defects show a positive dipolar defect contribution (DDC) to the , whereas the dipolar defects () show a negative DDC to the . The dipolar defects ( ‐ and ) can help improve the temperature stability of . The 0.4% MnO‐doped KNN‐0.045BNZ ceramics sintered in reducing atmosphere show excellent piezoelectric constant d₃₃ = 300 pC/N and 0.2% MnO‐doped KNN‐0.045BNZ ceramics sintered in air possess optimal piezoelectric constant d₃₃ = 290 pC/N.

中文翻译：

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在不同气氛下烧结的KNN基陶瓷的相结构和温度稳定性的缺陷工程

MnO掺杂的0.955K _0.5 Na _0.5 NbO ₃ -0.045Bi _0.5 Na _0.5 ZrO ₃（缩写为KNN-0.045BNZ）陶瓷是通过传统的固态烧结方法在还原气氛中制备的（ = 1×10 ^{− 10}  atm）和空气。对于在还原性气氛中烧结的陶瓷，陶瓷中仅存在Mn ²⁺离子，它们优先占据x  =  0.2-0.4处A位的阳离子空位，而Mn ²⁺离子代替B位的Zr ⁴⁺离子形成缺陷。 （）在x  > 0.4。对于在空气中烧结的陶瓷，此处混合存在Mn 2 ⁺，Mn ³⁺和Mn ⁴⁺离子。在x  = 0.2-0.4时，Mn ²⁺离子优先占据A-位中的阳离子空位，然后在x  > 0.4时，Mn ²⁺离子替代B-位中的Zr ⁴⁺离子。同时，Mn ³⁺离子和Mn ⁴⁺离子替代B站点中的Nb ⁵⁺离子，在x  = 0.2-0.8时形成缺陷（）。（，和）偶极缺陷对器件的正偶极缺陷贡献（DDC）   ，而偶极缺陷（）显示负直流电负。偶极缺陷（‐和）可以帮助改善硅的温度稳定性。在还原气氛中烧结的0.4％MnO掺杂的KNN-0.045BNZ陶瓷表现出优异的压电常数d ₃₃  = 300 pC / N和在空气中烧结的0.2％MnO掺杂的KNN-0.045BNZ陶瓷具有最佳的压电常数d ₃₃  = 290 pC / N.