Electron Diffraction and Imaging of Crystal Defects and Surfaces

这项研究是为了发展先进的电子显微镜技术及其在材料科学中的应用。感兴趣的具体技术是扫描透射电子显微镜（STEM）的在线全息成像和高角度环形暗场（HAADF） STEM成像。在线全息技术有望成为一种不需要更高加速电压就能提高STEM分辨率的可行方法。HAADF成像将非常适合研究晶体缺陷和表面层。特别是，上述技术将被应用于研究钛酸钡薄晶体中的铁电畴结构。这项研究的结果预计将对我们表征技术上重要的材料系统的能力产生重大影响。

This research is for the development of advanced electron microscopy techniques and their use in material science. Specific techniques of interest are in-line holography in a scanning transmission electron microscope (STEM) and high-angle annular dark-field (HAADF) STEM imaging. In-line holography promises to be a feasible means to enhance STEM resolution without the requirement of higher accelerating voltage. HAADF imaging will be well suited to study crystal defects and surface layers. In particular, the above techniques will be applied to studying ferroelectric domain structures in thin crystals of barium titanate. The results of this research are expected to have a major impact on our ability to characterize technologically important material systems.