Dear Khawla Al-saidi.

you should go through the following presentation:

http://prism.mit.edu/xray/oldsite/CrystalSizeAnalysis.pdf

Crystallite size determination is no simple task, which can be explained in a few sentences.

Get familiar with 'Scherrer equation' and 'Williamsen-Hall plot'.....

Good luck.

https://www.researchgate.net/post/How_do_I_calculate_nanocrystallite_size_by_Debye-Scherrer_equation_using_XRD

https://instanano.com/characterization/theoretical/xrd-size-calculation/

http://mahendrakoppolu.blogspot.com/2013/07/online-crystallite-size-calculator.html

Good luck!

First Calculate the FWHM from XRD plot and then put the value in D=0.9λ/(β cos θ) . β is the line broadening at half the maximum intensity (FWHM) . θ is the Bragg angle. λ is the X-ray wavelength

First plot your data in origin. then a single peak. measure the FWHM(full width at half maxima) then by using the Debye Scherrer formula particle size=(0.9*lamda)/(FWHM*cos(theta)). you can use software like MAUD to do Rietveld refinement and you will get the particle size.

thank you.

I answer you if you are using X'pert software.

1. find the crystallography information file (CIF) of the phase you obtained from the http://www.crystallography.net/cod/search.html

2. file-insert the cif file.

3. use the Reitveld menu in automatic form

4. start to complete the refinement by changing from automatic to semi-auto and selecting the parameters in refinement panel such as background, peak shape etc.

5. by checking the Agreement Index in data panel you can understand the your applying reefing is good or not, because after each refinement this number should decrease.

6 normally if agreement index

Check this site https://instanano.com/characterization/theoretical/xrd-size-calculation/