During high‐temperature crystal growth, lattice defects will inevitably form inside piezoelectric materials, which can be a hindrance for performance optimization. Through appropriate atmosphere control during sintering, defect levels inside the piezoelectric material can be regulated. Herein, CaZrO₃‐modified (K, Na)NbO₃‐based lead‐free piezoelectric ceramics with a nominal composition of 0.95(Na_0.49K_0.49Li_0.02)(Nb_0.8Ta_0.2)O₃‐0.05CaZrO₃ are produced by sintering in an oxygen‐rich atmosphere. Compared with an air‐sintered sample, the piezoelectric constant of the oxygen‐sintered sample has greatly improved 15% up to 390 pC/N, which is comparable to commercial lead‐based counterparts. In addition, the planar electromechanical coupling factor k_p is enhanced from 0.46 to 0.52. A qualitative model related to defect engineering is proposed to support the experimental observations. Our results indicate the feasibility of purposely optimizing the piezoelectric performance by sintering atmosphere control.

中文翻译：

---

通过烧结气氛控制抑制基于CaZrO3修饰的（K，Na）NbO3的无铅压电陶瓷中的缺陷

在高温晶体生长期间，不可避免地会在压电材料内部形成晶格缺陷，这可能会阻碍性能优化。通过在烧结过程中进行适当的气氛控制，可以调节压电材料内部的缺陷水平。此处，标称成分为0.95（Na _0.49 K _0.49 Li _0.02）（Nb _0.8 Ta _0.2）O ₃ ‐0.05CaZrO _3的CaZrO ₃改性（K，Na）NbO ₃基无铅压电陶瓷通过在富氧气氛中烧结生产的。与空气烧结的样品相比，氧气烧结的样品的压电常数高达390 pC / N时提高了15％，这与商业铅基样品相当。此外，平面机电耦合系数k _p从0.46提高到0.52。提出了与缺陷工程相关的定性模型以支持实验观察。我们的结果表明通过烧结气氛控制有意优化压电性能的可行性。