现代透射电子显微技术在多铁材料研究中的应用

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。

Modern transmission electron microscopy and its application to multiferroic materials

Recent progress of a variety of modern transmission electron microscopy(TEM) techniques and their applications to multiferroic materials are briefly reviewed. It is emphasized that numerous significant structural issues in multiferroic material science could be well addressed by means of TEM-based techniques. For instance, atomic-resolution scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) are invaluable for determining the atomic structure, valence states and electronic structure of the controllable interface in multiferroic heterostructures. High-quality high-resolution TEM and STEM images with spatial resolution better than 1Å 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 structure 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 mechanism in multiferroics.