How can one find lattice parameter using SAED (selected area electron diffraction) pattern?
looking for previous discussions in ResearchGate; for example, and many others:
https://www.researchgate.net/post/How_can_I_analyze_the_TEM_diffraction_pattern
1) find out the accelerating voltage u used for the SAED pattern
2) find out the wavelength of the e-beam relative to the voltage (\lambda)
3) find out the camera length for ur pattern (L)
4) measure the distance between a diffracted spot and the centre spot (R_i)
4) calculate out the space distance (d) from : R_i*d = \lambda * L
5) calculated lattice parameter (a) from R_i (this step is different for different crystal type, but u can find the formula on a text book)
Hope this is helpful. Cheers.
Here is a cool website which shows you how to index cubic structures easily. Non cubic structures are more complicated and you usually have to measure d-spacings to find the zone axis of the incident beam, and then simulate the diffraction with some software such as crystal maker to see if you get the same pattern. Crystal Maker is really good because you can upload CIF file from the American Mineral Database.
If you need more detailed instructions for indexing non cubic electron patterns, just let me know. Cheers.
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