A Quantitative Analysis Method of Material Structure Based on TEM Haadf Image

Abstract

The invention provides a material structure quantitative analysis method based on a transmission electron microscope HAADF image. The method is characterized by obtaining the coordinate position of each atom lattice in a transmission electron microscope high-resolution image through the image processing technique to obtain integral intensity of each atom and neighbourhood normalized intensity; and by fully combining the relation between HAADF imaging principle and intensity information, obtaining some quantitative information on the basis of qualitative research of the HAADF image. Through the data of the atomic lattice coordinates and normalized intensity and the like, a plurality of quantitative structure information can be obtained through analysis. In the method, the determination of the atom lattice coordinates and integral intensity is scientific and reasonable; application of the neighbourhood normalized intensity avoids the influence due to the case that the material (especially the polycrystal nanometer material) has larger range of structure fluctuation and defects; and the structure information can be summarized and analyzed quickly, and enormous workloads and errors due to manual measurement are prevented. The method has the advantages of accurate result, wide application range and high operability and the like.

Description

Technical field: [0001] The invention relates to a quantitative analysis method for material structure based on high-resolution HAADF image processing of a transmission electron microscope, and belongs to the field of image processing and material structure analysis. Background technique: [0002] The microstructure of a material is the basis for its physical properties and practical applications. Transmission Electron Microscopy (TEM for short) high-resolution (atomic resolution) imaging technology is an effective method for studying the microscopic structure of materials, especially the atomic scale structure. The annular high-angle dark field image (HAADF) under the scanning transmission electron microscope (STEM) can not only directly observe the crystal structure of the material, but also has a certain ability to distinguish atomic elements. Specifically, the contrast (atomic lattice intensity value) of the HAADF image is roughly proportional to the square of the atomi...

AI Technical Summary

Problems solved by technology

Although high-resolution HAADF images contain rich structural information, it is difficult for us to effectively extract and analyze them in most cases. There are mainly the following problems: 1. Generally, HAADF images are intensity-related grayscale images It is difficult to directly obtain quantitative structural information corresponding to atomic occupancy from these images; 2. For complex systems, such as different types of atoms in multi-element materials often occupy the same lattice point, the intensity of the HAADF image will be As a result of the common mixing of various elements, it is difficult to directly give the specific occupancy and distribution information of various atoms from the figure; 3. For nanoparticles or polycrystalline materials, due to factors such as irregular shapes and surface defects of the particles, the Different regions of its grains show different intensities, which increases the difficulty of structural analysis and even introduces some artifacts

Although some professional software for transmission electron microscopy, such as Gatan's DigtalMicrograph, etc., provide some high-resolution image processing methods, such as Fourier transform, filtering, intensity and lattice distance measurement and reading, etc., these processing methods It does not satisfy all data analysis very well, and at the same time shows very low efficiency or even completely powerless on some specific issues

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