Effects of different thermal conditions on lead-free (BiBa)(FeTi)O ceramics were studied to reduce secondary phase formation, regulate bismuth vacancies and resulting oxygen vacancies, and Fe ions valence transition during the heat treatment process. The optimal thermal conditions led to a higher = 200 pC/N and a = 420 pm/V. A/B-sites ions replacement in BF35BT, BF35BT-Zr, and BF35BTSZ ceramics were prepared to reveal the effects of different Zr or Sr-Zr-contents. A maximum tetragonality (/) was estimated for the single doping (Zr) and co-doping (Sr and Zr) cases. For Zr = 0.02, the electric field-induced strain reached its maximum value of = 562 pm/V. Similarly, a strain of = 701 pm/V was observed for Sr-Zr = 0.02. Additionally, the improved to 870 pm/V (90 °C) in Zr = 0.02 and 1130 pm/V (120 °C) in Sr-Zr=0.02. The presence of local structural heterogeneity causes the domain size to decrease as it moves from the micro to the nanoscale. The results demonstrate that improved performance can be associated with reduced concentration of oxygen vacancies, nanodomains by local structural heterogeneity, high lattice anisotropy, higher relative density, and appropriate grain size.

中文翻译：

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B 位和 A/B 位共掺杂对无铅压电体高机电响应的晶格畸变和缺陷浓度的影响


研究了不同热处理条件对无铅 (BiBa)(FeTi)O 陶瓷的影响，以减少热处理过程中第二相的形成、调节铋空位和由此产生的氧空位以及 Fe 离子价态跃迁。最佳热条件导致更高的 = 200 pC/N 和 a = 420 pm/V。制备了 BF35BT、BF35BT-Zr 和 BF35BTSZ 陶瓷中的 A/B 位离子置换，以揭示不同 Zr 或 Sr-Zr 含量的影响。对于单一掺杂（Zr）和共掺杂（Sr 和 Zr）情况估计了最大四方性（/）。当 Zr = 0.02 时，电场引起的应变达到最大值 = 562 pm/V。类似地，对于 Sr-Zr = 0.02，观察到应变 = 701 pm/V。此外，Zr = 0.02 时提高至 870 pm/V (90 °C)，Sr-Zr=0.02 时提高至 1130 pm/V (120 °C)。局部结构异质性的存在导致域尺寸随着从微米尺度移动到纳米尺度而减小。结果表明，性能的提高可能与氧空位浓度的降低、局部结构异质性形成的纳米域、高晶格各向异性、较高的相对密度和适当的晶粒尺寸有关。