Coupled polarization and nanodomain evolution underpins large electromechanical responses in relaxors
Coupled polarization and nanodomain evolution underpins large electromechanical responses in relaxors
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DOI：
10.1038/s41567-022-01773-y
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发表时间：
2022-10
期刊：
影响因子：
19.6
通讯作者：
Jieun Kim;Abinash Kumar;Y. Qi;H. Takenaka;P. Ryan;D. Meyers;Jong-Woo Kim;Abel Fernandez;Z. Tian;A. Rappe;J. Lebeau;L. Martin
中科院分区：
文献类型：
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作者：
Jieun Kim;Abinash Kumar;Y. Qi;H. Takenaka;P. Ryan;D. Meyers;Jong-Woo Kim;Abel Fernandez;Z. Tian;A. Rappe;J. Lebeau;L. Martin
理解弛豫铁电体中极化旋转过程中纳米级极性结构的演变和作用是材料科学和凝聚态物理学中的一个长期挑战。这些纳米级极性结构的特征在于极性纳米畴，其被认为在实现弛豫剂的大的可磁化性中起关键作用。使用外延应变，我们稳定的中间步骤极化旋转过程中的外延薄膜的一个典型的弛豫和研究极化和极性纳米畴的共同演变。我们的多模态方法允许详细检查极化和极性纳米畴之间的相关性;阐明了局部化学，应变和电场对其共同进化的影响;并揭示了应变在实现弛豫体中的大型机电耦合中的未被充分认识的作用。随着应变的增加，极性单元的化学驱动无序和应变驱动有序之间的竞争加剧，这表现在极化旋转的中间步骤中倾斜和伸长的极性纳米畴的共存。我们的研究结果表明，极性纳米畴配置之间的结构转变的基础极化旋转和大机电耦合的弛豫。
Understanding the evolution and role of nanoscale polar structures during polarization rotation in relaxor ferroelectrics is a long-standing challenge in materials science and condensed-matter physics. These nanoscale polar structures are characterized by polar nanodomains, which are believed to play a key role in enabling the large susceptibilities of relaxors. Using epitaxial strain, we stabilize the intermediate step during polarization rotation in epitaxial films of a prototypical relaxor and study the co-evolution of polarization and polar nanodomains. Our multimodal approach allows for a detailed examination of correlations between polarization and polar nanodomains; illuminates the effect of local chemistry, strain and electric field on their co-evolution; and reveals the underappreciated role of strain in enabling the large electromechanical coupling in relaxors. As the strain increases, the competition between chemistry-driven disorder and strain-driven order of the polar units intensifies, which is manifested in the coexistence of inclined and elongated polar nanodomains in the intermediate step of polarization rotation. Our findings establish that structural transitions between polar nanodomain configurations underpins the polarization rotation and large electromechanical coupling of relaxors.