Continuous rotation precession electron diffraction tomography method

A technique of electron diffraction and tomography, which is used in material analysis, instruments, and measurement devices using wave/particle radiation. , the effect of small crystal size and simple collection method

Pending Publication Date: 2022-05-06
苏州青云瑞晶生物科技有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, cRED cannot perform dynamic refinement, and the fine structure of the sample cannot be determined

Method used

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  • Continuous rotation precession electron diffraction tomography method
  • Continuous rotation precession electron diffraction tomography method
  • Continuous rotation precession electron diffraction tomography method

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example 1

[0041]Example 1: Inorganic magnesium molybdate using the method of the present invention (cPEDT) and the PEDT collection method, the results of refinement after kinetic refinement, as shown in Table 1. Table 1 is inorganic magnesium molybdate, the crystal structure refinement results list collected and analyzed by this method (cPEDT) and PEDT for the same sample particles. cPEDT has a lower refinement figure of merit R obs , wR obs , R all , wR all and residual potential density, indicating that the diffraction data provided by this method are more accurate and the crystal structure is more reasonable.

[0042] Table 1

[0043]

example 2

[0044] Example 2: In another example of the present invention, it can be proved that the electron beam-sensitive organic compound benzamide can also restore a high-precision crystal structure, and crystals with smaller sizes are required compared to X-rays. Table 2 shows the diffraction data and structure refinement results collected by the cPEDT and SC-XRD (X-ray single crystal diffraction) methods for the organic substance dibenzamide. Among them, the refined quality factor R value and the residual electron cloud density are similar to the refined results of X-ray single crystal diffraction, which proves that this method has the same accuracy as X-ray single crystal diffraction. At the same time, the structure based on cPEDT data can find the position of clear hydrogen atoms from the difference Fourier potential density distribution, such as Figure 5 shown. Also note that X-ray single crystal diffraction usually requires crystals with a size of more than 100 μm, while the ...

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Abstract

The invention relates to a method for collecting data of three-dimensional electron diffraction, in particular to a method for collecting data of three-dimensional electron diffraction, in particular to a method for collecting data of three-dimensional electron diffraction, in particular to a method for collecting data of three-dimensional electron diffraction, in particular to a method for collecting data of three-dimensional electron diffraction, which is named as continuous precession electron diffraction tomography (cPEDT), and the method is a combination of precession electron diffraction tomography (PEDT) and continuous precession electron diffraction (cRED). By using the cPEDT method, the unnecessary electron dose introduced in the step-by-step process in the PEDT method can be avoided, and meanwhile, the data collected by the cPEDT can be used for dynamic refinement so as to determine the accurate structure of the material. According to the method, the application of three-dimensional electron diffraction on some electron beam sensitive materials, such as metal-organic framework materials (MOFs), covalent organic framework materials (COFs), some organic matter crystals, some inorganic matter crystals and the like, can be promoted.

Description

technical field [0001] The present invention relates to a method for determining the crystal structure of a crystal by continuous rotating precession electron diffraction using an electron microscope. The electron method uses an electron beam to irradiate the crystal. The steps of the method are: [0002] 1. Provide a sample with one or more crystals in it, [0003] 2. Identify the crystals to be analyzed on the sample, [0004] 3. Turn on the screw-in device and confirm the screw-in angle [0005] 4. The electron microscope emits electron beams, rotates the crystal continuously and records the diffraction pattern of the crystal [0006] 5. Determine the crystal structure by analyzing the recorded diffraction patterns. Background technique [0007] The state of solid matter can be divided into two categories: crystalline (or crystal) and amorphous (or amorphous, glass, etc.). Molecules, atoms or ions in crystalline substances (crystals) are arranged periodically and orde...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N23/207
CPCG01N23/207
Inventor 孙俊良沈弈寒孙文甲刘扬周钲洋
Owner 苏州青云瑞晶生物科技有限公司
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