近日，美国阿贡国家实验室的Yue Cao&Hao Zheng及其研究小组与美国加州大学伯克利分校的Lane W. Martin等人合作并取得一项新进展。经过不懈努力，他们揭示弛豫铁电体中层次极性分层的非均匀场响应。相关研究成果已于2024年6月28日在国际权威学术期刊《科学》上发表。

通过利用X射线相干纳米衍射技术，该研究团队揭示了弛豫铁电材料0.68PbMg_1/3Nb_2/3O₃-0.32PbTiO₃ （简称PMN-0.32PT）中极性纳米畴（PNDs）如何交错自组装成一种独特的单向介观结构，研究团队称之为“极性分层”。研究人员进一步探索了层内和层间PNDs在电场驱动下的高度非均质响应，并建立了这些响应与局部应变以及PND壁性质的关联。

这一观察结果凸显了层次晶格组织对宏观材料性质的关键作用，并为理解和设计弛豫体以及广泛的量子和功能材料提供了指导原则。

据悉，要深入揭示弛豫铁电体出色机电响应的微观机制，不仅要洞察极性纳米畴（PNDs）在原子尺度的形成过程，还需掌握PNDs在较长距离上的排列和受激响应的规则。

附：英文原文

Title: Heterogeneous field response of hierarchical polar laminates in relaxor ferroelectrics

Author: Hao Zheng, Tao Zhou, Dina Sheyfer, Jieun Kim, Jiyeob Kim, Travis D. Frazer, Zhonghou Cai, Martin V. Holt, Zhan Zhang, J. F. Mitchell, Lane W. Martin, Yue Cao

Issue&Volume: 2024-06-28

Abstract: Understanding the microscopic origin of the superior electromechanical response in relaxor ferroelectrics requires knowledge not only of the atomic-scale formation of polar nanodomains (PNDs) but also the rules governing the arrangements and stimulated response of PNDs over longer distances. Using x-ray coherent nanodiffraction, we show the staggered self-assembly of PNDs into unidirectional mesostructures that we refer to as polar laminates in the relaxor ferroelectric 0.68PbMg_1/3Nb_2/3O₃-0.32PbTiO₃ (PMN-0.32PT). We reveal the highly heterogeneous electric-field–driven responses of intra- and interlaminate PNDs and establish their correlation with the local strain and the nature of the PND walls. Our observations highlight the critical role of hierarchical lattice organizations on macroscopic material properties and provide guiding principles for the understanding and design of relaxors and a wide range of quantum and functional materials.

DOI:10.1126/science.ado4494

Source: https://www.science.org/doi/10.1126/science.ado4494