Deriving from strong temperature dependence of polymorphic phase boundaries, piezoelectric constant of potassium sodium niobate (K_0.5N_0.5NbO₃)‐based ceramics is sensitive to the poling temperature. Here, an effective strategy of doping rare earth (RE) elements is proposed to solve this issue. Piezoelectric constant (d ₃₃ ~ 440 pC/N) can be well kept in 0.965K_0.45Na_0.55Nb_0.96Sb_0.04O₃‐0.035(Bi_0.75Dy_0.25)_0.5Na_0.5HfO₃ ceramics at a wide poling temperature range (35‐120°C) by the method of replacing Bi³⁺ with rare earth dysprosium, and importantly, this method can be effectively expanded to other RE elements. The high piezoelectricity roots in the multiphase coexistence with the addition of RE elements. The dull sensitivity of poling temperature is analyzed by microstructure information, that is, ferroelectric domains can be well rotated under a wide temperature range by introducing RE, which is responsible for the stabilized piezo‐response against the poling temperature. Moreover, comparing with Bi³⁺, a lower electronegativity of RE³⁺ may effectively reduce the micro‐stress produced by lattice distortion, also yielding to the lattice softening and the easier domain rotation.

中文翻译：

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高性能铌酸钾钠压电陶瓷的极化温度不敏感压电常数

由于多态相界对温度的强烈依赖性，铌酸钾钠（K _0.5 N _0.5 NbO ₃）基陶瓷的压电常数对极化温度敏感。在此，提出了一种掺杂稀土元素的有效策略来解决这个问题。压电常数（d ₃₃  〜440 PC / N）可以很好地保持在0.965K _0.45钠_0.55的Nb _0.96 Sb的_0.04 ø ₃ -0.035的（Bi _0.75镝_0.25）_0.5的Na _0.5的HfO ₃通过用稀土替代Bi ³⁺的方法，在宽极化温度范围（35-120°C）的陶瓷中，重要的是，该方法可以有效地扩展到其他稀土元素。高压电性源自添加RE元素的多相共存。通过微观结构信息分析了极化温度的钝感，即通过引入RE可以在宽温度范围内很好地旋转铁电畴，这对极化温度具有稳定的压电响应。此外，与Bi ³⁺相比，RE ^3+的电负性较低 可以有效地减少晶格畸变产生的微应力，也可以使晶格软化并简化磁畴旋转。