Nano-structure analysis with BF STEM

使用 BF STEM 进行纳米结构分析

• 批准号: 15560024
• 负责人: WATANABE Kazuto
• 金额: $ 2.37万
• 依托单位: Tokyo Metropolitan College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560024/
• 关键词: BF STEM; HAADF STEM; Bloch wave; ナノ構造解析; interface; STEM; amorphous

Much knowledge was given through a study of nanoatomic structure analysis in a nanometer scale domain by a bright field scanning transmission electron microscope (BF STEM). Main points are summarized as follows :(1)Increasing semiangle of an incident beam and semiangle of detector, HABF STEM image gets the same level spatial resolution as an HAADF STEM image, so that this HABF STEM image could be used for nano structure analysis in a nanometer scale domain.(2)It is found that HABF STEM image can be indicated in convolution from a dynamics calculation based on three-dimensional Bloch waves(3)The image processing method combining convolution indication with maximum entropy method improves quality of an image drastically and can extend information limit, thus being very effective.(4)The translation symmetry and two-dimensional point group can provide a large decrease in number of partial plane waves. In the case of a good symmetry crystal, this method is able to completely do 1/40 in calculation time.(5)Using above symmetrical idea, it becomes possible for a dynamical calculation of defects such as interfaces. As a result, precise structure analysis is enabled from a quantitative comparison between dynamical simulation and an experiment image.Through this study, the image formation mechanism for BF STEM and a general view of HAADF STEM have been made clear. A further development of device and improvement of analysis could be able to build precise atomic structure analytical method.

通过利用亮场扫描电子显微镜(BF STEM)对纳米尺度范围内的纳米原子结构分析进行研究，提供了许多知识。主要内容概括如下：(1)增大入射光束的半角和探测器的半角，HABF STEM图像可以获得与HAADF STEM图像相同的空间分辨率，从而可以用于纳米尺度域的纳米结构分析。(2)基于三维Bloch波的动力学计算发现，HABF STEM图像可以卷积表示。(3)卷积表示和最大熵方法相结合的图像处理方法大大提高了图像的质量，并扩展了信息限制。平移对称性和二维点群可以大大减少局部平面波数。在晶体对称性较好的情况下，这种方法的计算时间可以完全达到1/40。(5)利用上述对称思想，可以对界面等缺陷进行动力学计算。通过动态模拟和实验图像的定量对比，可以对高炉STEM进行精确的结构分析。通过本研究，对高炉STEM的图像形成机理和HAADF STEM的总体情况有了明确的认识。随着仪器的进一步发展和分析水平的提高，有可能建立精确的原子结构分析方法。

项目成果

Role of surface amorphous film in high-resolution annular dark field STEM imaging

表面非晶薄膜在高分辨率环形暗场 STEM 成像中的作用

• 发表时间: 2004
• 期刊: Ultramicroscopy 99
• 作者: Kazuto Watanabe;Eiji Asano;Takashi Yamazaki;Yoshio Kikuchi;Iwao Hashimoto;K.Watanabe et al.;K.Watanabe et al.;T.Yamazaki et al.
• 通讯作者: T.Yamazaki et al.

Symmetry of BF- and HAADF-STEM image calculations

BF- 和 HAADF-STEM 图像计算的对称性

• 发表时间: 2004
• 期刊: Ultramicroscopy 102
• 作者: Kazuto Watanabe;Eiji Asano;Takashi Yamazaki;Yoshio Kikuchi;Iwao Hashimoto
• 通讯作者: Iwao Hashimoto

Symmetry of BF-and HAADF-STEM image calculations

BF-和 HAADF-STEM 图像计算的对称性

• 发表时间: 2004
• 期刊: Ultramicroscopy 102
• 作者: Kazuo Watanabe;Eiji Asano;Takashi Yamazaki;Yoshio Kikuchi;Iwao Hashimoto
• 通讯作者: Iwao Hashimoto

Lattice imaging in low-angle and high-angle bright field scanning transmission electron microscopy

低角度和高角度明场扫描透射电子显微镜中的晶格成像

• 发表时间: 2004
• 期刊: Acta Cryst. A60
• 作者: Kazuto Watanabe;Eiji Asano;Takashi Yamazaki;Yoshio Kikuchi;Iwao Hashimoto;K.Watanabe et al.
• 通讯作者: K.Watanabe et al.

Expanded dynamical HAADF STEM image simulation using Bloch wave method

使用布洛赫波方法扩展动态 HAADF STEM 图像模拟

• 发表时间: 2006
• 期刊: Acta Cryst. A(印刷中)
• 作者: Takashi Yamazaki;Kazuto Watanabe;Koji Kuramochi;Iwao Hashimoto
• 通讯作者: Iwao Hashimoto