现代透射电子显微技术在多铁材料研究中的应用  

Modern transmission electron microscopy and its application to multiferroic materials

作　　者：杨槐馨[1] 李俊[1] 张颖[1] 马超[1] 李建奇[1] 

机构地区：[1]中国科学院物理研究所北京凝聚态物理国家实验室,北京100190

出　　处：《物理》2014年第2期105-116,共12页Physics

基　　金：国家重点基础研究发展计划(批准号:2011CB921703;2014CB921002);国家自然科学基金(批准号:912211012;51272277;11374349)资助项目

摘　　要：文章简要介绍了材料科学研究中被广泛应用的透射电子显微(TEM)技术及其在多铁材料研究中的应用,并给出了几个典型案例:利用球差矫正原子分辨扫描透射电子显微术(STEM),并和电子能量损失谱(EELS)相结合,分析多铁异质结界面处的原子分布、离子价态和化学键的变化;结合球差矫正原子分辨透射电子显微图像(HRTEM)和STEM图像,分析多铁材料中的局域对称性破缺和电极化特性;利用原位变温及电/磁场加载技术,研究多铁材料中的结构相变和电畴/磁畴的动态演变特性。文章特别指出,现代透射电子显微学是全面分析理解多铁材料局域微结构,探讨多铁耦合机制及其物理根源的有效手段。Recent progress of a variety of modem transmission electron microscopy （TEM） techniques and their applications to multiferroic materials are briefly reviewed. It is empha- sized that numerous significant structural issues in multiferroic material science could be well ad- dressed by means of TEM-based techniques. For instance, atomic-resolution scanning transmis- sion electron microscopy （STEM） and electron energy-loss spectroscopy （EELS） are invaluable for determining the atomic structure, valence states and electronic structure of the controllable in- terface in multiferroic heterostructures. High-quality high-resolution TEM and STEM images with spatial resolution better than 1 A ensure the direct observation of local dipoles and mapping of the polarization field. The new generation TEM facilities combined with in-situ cooling/heating and electric/magnetic field holders allow us to capture the dynamic characteristics of the atomic struc- ture and ferroelectric/magnetic domains and to understand the interaction between different order parameters, which will provide valuable insight into the physical origin of the coupling mecha- nism in multiferroics.

关 键 词：透射电子显微镜 多铁材料 原位TEM技术 相变 畴结构 

分 类 号：O469[理学—凝聚态物理]