菱面体畸变的钙钛矿结构多铁性氧化物薄膜畴界精细结构  

Domain structure of multiferroic oxide thin films with rhombohedral perovskite structure

作　　者：詹倩[1] 于荣[2] CHU Y H MARTIN L W RAMESH R 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]清华大学材料系,北京电镜中心,北京100084 [3]Department of Materials Science and Engineering, University of California, Berkeley, Colifornia 94720 and Department of Physics, University of California, Berkeley, California 94720

出　　处：《电子显微学报》2010年第5期425-429,共5页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.50971015);教育部留学回国人员科研启动基金资助项目

摘　　要：畴是所有铁性材料的一个共同本质特性,畴及畴界的结构极大影响着材料性能。本文应用高分辨透射电子显微学和定量电子显微学,在原子尺度定量研究了钙钛矿菱面体结构多铁性薄膜BiFeO3的109°畴界的精细结构,包括畴界附近阳离子位移及局部铁电极化分布。结果表明:正是由于畴界附近原子发生微小位移,导致材料能带的变化,带隙减小,从而在绝缘BiFeO3中产生独特的导电性能。这不仅为研究铁电极化反转和磁电效应等科学问题提供关键的定量结构信息,同时也促进相关材料的设计和性能优化。Domain is the intrinsic characteristic of all of the ferroic material. The structure of domain and domain wall have significant effects on the physical properties of ferroic material. The 109 °domain wall structure of complicated rhombohedral perovskite BFO thin films at atomic scales was studied by means of high resolution electron microscopy and quantitative electron mierscopy. The displacement of cations and local polarization distributions across the domain walls were determined. The results show that the observed room temperature conductivity at domain walls in the insulating muhiferroic BiFeO3 correlates with the structural driven changes, resulting in a decrease in the bandgap at the domain wall. The results would： provide quantitative structural information for understanding the polarization reversing and magnetoeleetric coupling in multiferroics, and for the research and development of related devices in electronics industry.

关 键 词：多铁 畴 微观结构 电子出射波重构 

分 类 号：TB383.2[一般工业技术—材料科学与工程]