#Dm3 file singlecrystal series
(b)įor the traditional SAED analysis, the examined crystal should be series tilt to record symmetric zone axis patterns (ZAP) which will be indexed to determine dimensions of the unit cell . However, other problems will be encountered in electron diffraction analysis:įor the electron diffraction of the minor phases, it is impossible to get an ideal ring pattern to perform phase analysis as that of XRD, which requires the examined region containing an infinite number of individual particles with completely random orientation distribution . For the electron diffraction, we can focus the incident electron beam on the minor phase to record high-quality pattern within several seconds. It indicates that an accurate d-spacing table which is a file with a list of diffraction peaks, e.g., a series of d h k l and I h k l, or 2 θ and I h k l, is essential for both of the phase analysis and the unit cell determination based on the X-ray & electron diffraction.Ĭommonly, diffracted signals from minor phases are overwhelmed by that of the main structure in the X-ray experiments even if with several hours’ collection, consequently it is complicated to carry out a confident phase analysis by the technology of X-ray diffraction. Both of them have been well established for X-ray or electron diffraction, as listed in Table 1.
Phase analysis is a fundamental step for the material synthesis and characterization, and it can be used to optimize the synthetic process The unit cell determination is the first step to ab initio solve the crystal structure of the unknown phase. For example, the compressive strength of the cement paste is enhanced by 50% even with only 0.045%–0.15% multi-walled carbon nanotubes graphene wrapped sulfur particles has high and stable specific capacities ∼600 mAh/g over more than 100 cycles . By comparison with X-ray diffraction (XRD), SAED patterns or diffractograms derived from HRTEM images can give rich crystallographic information of the minor phases in which the diffracted signals are quite weak and usually cannot be detected effectively in XRD, but are rather important for excellent physical or chemical properties of materials. Transmission electron microscopy (TEM) is a powerful technique to perform microstructural analysis at atomic scale both in the real & reciprocal space by a combination of the high-resolution transmission electron microscope (HRTEM) and the selected-area electron diffraction (SAED) techniques . Moreover, an accurate d-spacing table derived from spots extension can be used to determine the unit cell of the unknown crystal.Īdditional comments: The program can also be obtained from The azimuthal rotation-average projection is applied to extract the intensity profile, linear image and its surface plot for the phase analysis. Solution method: Gaussian filtering and Gaussian fitting are implemented in ElectronDiffraction tools to automatically measure diffraction spots for the pattern indexing and the extraction of the d-spacing table. Nature of problem: It is a time-consuming procedure with a large analysis error for the traditional TEM analysis based on the SAED pattern or HRTEM images. Programming language: DigitalMicrograph scripting language
#Dm3 file singlecrystal license
Licensing provisions: GNU Public License GPLv3 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. 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.
#Dm3 file singlecrystal software
The program was written as a package of DigitalMicrograph, a very popular software to record and analyze the data of transmission electron microscopes (TEM).
For the need of the daily-used diffraction analysis, we present a new processing & analysis package for electron diffraction pattern, ElectronDiffraction tools. 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. Three traditional methods of electron diffraction analysis are pattern indexing, phase identification, and unit cell determination. 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.
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