新型铁电拓扑结构的构筑及其亚埃尺度结构特性  

Construction of novel ferroelectric topological structures and their structural characteristics at sub-angström level

作　　者：王宇佳[1] 耿皖荣 唐云龙 朱银莲[1] 马秀良[1] Wang Yu-Jia;Geng Wan-Rong;Tang Yun-Long;Zhu Yin-Lian;Ma Xiu-Liang(Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China)

机构地区：[1]中国科学院金属研究所,沈阳材料科学国家研究中心,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016

出　　处：《物理学报》2020年第21期153-167,共15页Acta Physica Sinica

基　　金：中国科学院前沿科学重点研究项目(批准号:QYZDJ-SSW-JSC010);国家自然科学基金(批准号:51671194,51971223,51922100);沈阳材料科学国家研究中心项目(批准号:L2019R06,L2019R08,L2019F01,L2019F13)资助的课题.

摘　　要：铁电拓扑结构因其尺寸小而且具有优良的物理特性,有望应用于未来高性能电子器件中.本文从应变、屏蔽和外场等对于铁电材料至关重要的几个外部要素出发,结合薄膜厚度等材料内部参数,针对PbTiO3和BiFeO3这两种典型的铁电材料,简要总结新型铁电拓扑结构的形成及其在外场作用下的演变规律.利用具有亚埃尺度分辨能力的像差校正透射电子显微术呈现了相关拓扑结构的原子结构图谱,构建了针对PbTiO3体系的厚度-应变-屏蔽相图,系统归纳了两种材料中各种拓扑结构的形成条件.最后指出这两类铁电材料中易于调控出拓扑结构的几何维度体系,并指出像差校正透射电子显微术在表征铁电拓扑结构方面的重要作用,展望了未来可能的关注重点.In this paper,the recent progress of ferroelectric topologies is briefly reviewed with the emphasis on the important role of state-of-the-art aberration-corrected transmission electron microscopy in revealing the topological features in nanoscale ferroelectric materials.By identifying the ion displacement at a sub-angström level,the corresponding polarization distribution can be determined which uncovers the characteristics of topological structures.The formation mechanisms of ferroelectric topological structures and their evolutions under external fields are summarized from the perspective of strain,screening,and external fields for two prototypical ferroelectric materials,PbTiO3 and BiFeO3.For the PbTiO3,its topological structures such as fluxclosures,vortices,bubbles,skyrmions,and merons can be well demonstrated in a thickness-strain-screening phase diagram,which could be a guideline for better understanding the topological structures and also for the future exploration.For BiFeO3,its topological structures reported are classified as two categories:one is the unscreened topological structure such as vortices and the other is the screened topological structure(center-type domains).Finally,we present the prospects for the future development of the ferroelectric topologies.

关 键 词：铁电拓扑结构 像差校正透射电子显微术 PBTIO3 BIFEO3 

分 类 号：TM221[一般工业技术—材料科学与工程] O469[电气工程—电工理论与新技术]