Hi there!
I am using Fullprof for the first time to perform rietveld analysis of intercalated graphite samples. I have XRD data with me, and I entered the values of parameters as seen from databases on the internet. (except the value of parameter 'B')
I followed a youtube video to go about my work, and didn't enter any value in refinement section apart from fractional coordinates and cell parameters of graphite. Even though I had chosen to refine the 'c' parameter, my results do not show any expansion, despite showing a promising XRD graph. Moreover, my analysis completely fails to identify a significant peak, and converges to a wrong conclusion.
It would be great if anyone could guide me how I could go about it. I would appreciate it if you could answer keeping in mind that I am a beginner. (Also, if anyone could guide me through this process? Like, I could ask him/her doubts over personal message)
here you go
https://www.youtube.com/watch?v=3eA84qq0pvg
https://www.youtube.com/watch?v=yJ-uu5suZq8
Dear Vidisha,
FullProf software is a tool for refining structural parameters using diffraction patterns obtained by X-ray or neutron or other sources. It fitted two type of refinements (1) Lei-bail and (2) Rietveld refinement. For Rietveld refinement. For beginners, it is necessary that you performed Lei-bail fitting first for optimizing the lattice parameters, background, instrumental parameters etc. Then go for Rietveld refinements entering coordinates of atoms, occupancy and B parameters, a small value near unity and then refine B and coordinates. For all these processes you have to keep your patience. The youtube videos suggested by Syed Osama Ali will be also helpful.
I am more concern on the graphite itself rather than the software. I think it might be a good idea to find out the original structure of the graphite first. Is it highly perfect crystal or more disordered (turbostratic)? From there, you can have a good idea which peaks are visible and which are not. Perform xrd on the original graphite and compare the result to the intercalated graphite by using the standard search & match method so that you can figure out what and where thing went wrong. If nothing abnormal was found, then you can proceed to rietveld analysis.
I also want to mention that special cares must be done during xrd sample preparation due to the abnormal intensity factors of graphite. The details on the xrd technique is explained in the reference below.
https://www.researchgate.net/publication/228792710_Corrigendum_to_Specification_for_a_standard_procedure_of_X-ray_diffraction_measurements_on_carbon_materials_Carbon_42_2004_701-714
Good luck.
Article Corrigendum to “Specification for a standard procedure of X-...
I have uploaded a video on YouTube, it is for beginners and present one of easiest Way to do structural refinement using FullProf Suite https://www.youtube.com/watch?v=mWNpIIwEcDk
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