ElectronDiffraction tools, a DigitalMicrograph package for electron diffraction analysis

Microstructure analysis based on the electron diffraction patterns (ED or SAED) or high-resolution transmission electron microscopy images (HRTEM) has become a major technique for the local structural characterization of materials. Three traditional methods of electron diffraction analysis are pattern indexing, phase identification, and unit cell determination. But for the lack of analysis tools, most of the people usually manually measure the diffraction spots to index the diffraction pattern or measure a few lattice planes (fringes in HRTEM or diffraction rings) to perform phase analysis. For the need of the daily-used diffraction analysis, we present a new processing & analysis package for electron diffraction pattern, ElectronDiffraction tools. The program was written as a package of DigitalMicrograph, a very popular software to record and analyze the data of transmission electron microscopes (TEM). Autocorrelation and digital filter method were implanted in it to yield a high-quality Fourier transform diffractogram from an HRTEM image, Gaussian filter and Gaussian fitting were applied to locate diffraction spots with sub-pixel accuracy. It can automatically measure diffraction spots to index the spotty-like diffraction pattern of the known crystal; intensity profile or surface plot extracted from a diffraction pattern can be used to carry out phase analysis just like ‘Search-Match’ in XRD, and the extracted d-spacing table can be used to determine the unit cell of the unknown crystal.

基于电子衍射花样（electron diffraction, ED 或选区电子衍射（selected area electron diffraction, SAED））或高分辨透射电子显微镜图像（high-resolution transmission electron microscopy, HRTEM）的微观结构分析，已成为材料局部结构表征的主流技术。传统电子衍射分析方法主要包括花样标定、物相鉴定以及晶胞确定。但由于缺乏专用分析工具，当前多数研究者仍需手动测量衍射斑点以完成衍射花样标定，或通过测量少量晶面（高分辨图像中的晶格条纹或衍射环）来开展物相分析。为满足日常电子衍射分析的实际需求，我们开发了一款全新的电子衍射花样处理与分析工具包——ElectronDiffraction tools。该工具包基于当前主流的透射电子显微镜（transmission electron microscope, TEM）数据记录与分析软件DigitalMicrograph开发。工具包内置自相关与数字滤波算法，可从HRTEM图像中生成高质量的傅里叶变换衍射谱；同时采用高斯滤波与高斯拟合技术，实现亚像素级精度的衍射斑点定位。其可自动测量衍射斑点，完成已知晶体的斑点型衍射花样标定；从衍射花样中提取的强度分布曲线或三维表面图，可用于开展类似X射线衍射（X-ray diffraction, XRD）中“搜索-匹配”的物相分析；而提取得到的晶面间距表，则可用于确定未知晶体的晶胞参数。

搜集汇总

背景与挑战

背景概述

该数据集是一个用于电子衍射分析的DigitalMicrograph插件包，旨在自动化处理电子衍射图案和高分辨率透射电子显微镜图像，以进行微结构表征。它集成了自相关、数字滤波和高斯拟合等技术，能够高精度定位衍射斑点、索引已知晶体衍射图案、进行相分析并确定未知晶体的晶胞，适用于材料科学领域的局部结构研究。