The morphotropic phase boundary (MPB) plays an important role in ferroelectric materials. Typically, two phases coexist in materials near the MPB. Such materials usually exhibit large piezoelectricities, dielectricities, and actuation strains. In this work, we produce an MPB-like effect in hybrid electrically poled, mechanically depolarized (HEPMD) BaTiO3 and lead zirconate titanate ceramics where depolarized region A and vertical electrically poled region C intersect each other with a period of 400 μm in both in-plane directions. The polarization and strain of both HEPMD samples are over 3 times those of conventionally poled samples under unipolar electric loading. The large polarization and strain decrease steadily as the frequency increases and stabilize at approximately twice the values from the conventionally poled samples. Furthermore, the large polarizations and actuation strains of the HEPMD samples are fairly stable and change little after 30 000 cycles of operation. Under bipolar electric loading, the tendencies are similar and the coercive fields of the HEPMD samples are considerably smaller, which is similar to the MPB effect in traditional ferroelectric ceramics. Enhanced polarization and strain occur in HEPMD samples due to reversible ferroelectric domain switching during loading and unloading under large electric fields. In comparison, the small-signal properties, i.e., the d33 and dielectric properties, are slightly larger in HEPMD samples than in conventionally poled ones. The HEPMD method may be applied to all types of multiaxial ferroelectric ceramics to enhance actuation strain and polarization.

中文翻译：

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混合电极化、机械去极化铁电陶瓷中的类变相相界效应

同向相界 (MPB) 在铁电材料中起着重要作用。通常，两相共存于 MPB 附近的材料中。这种材料通常表现出大的压电性、介电性和驱动应变。在这项工作中，我们在混合电极化、机械去极化 (HEPMD) BaTiO3 和锆钛酸铅陶瓷中产生类似 MPB 的效应，其中去极化区域 A 和垂直电极区域 C 以 400 μm 的周期相互交叉平面方向。在单极电负载下，两种 HEPMD 样品的极化和应变是常规极化样品的 3 倍以上。大极化和应变随着频率的增加而稳定下降，并稳定在常规极化样品值的大约两倍。此外，HEPMD 样品的大极化和驱动应变相当稳定，并且在 30 000 次操作循环后变化很小。在双极电负载下，HEPMD 样品的矫顽场趋向相似，矫顽场小得多，这类似于传统铁电陶瓷中的 MPB 效应。由于在大电场下加载和卸载期间可逆的铁电畴切换，HEPMD 样品中出现增强的极化和应变。相比之下，HEPMD 样品的小信号特性，即 d33 和介电特性，比传统极化的样品略大。HEPMD 方法可应用于所有类型的多轴铁电陶瓷，以增强驱动应变和极化。