Rietveld refinement models the experimental XRD profile by accounting for the contribution of the instrument and of the crystalline phases present. You will need to know or measure some characteristcs of the instrument used that are used to calculate the instrument function -thus the contribution of the instrument to peak broadening, background and shape. You will also need a structure file for Si that is used to model the mineral contribution.

There are several software available for Rietveled, a few are open-source, here's a couple of my favorites:

Profex (BGMN): http://profex.doebelin.org/

FullProf: https://www.ill.eu/sites/fullprof/php/tutorials.html

GSAS: https://www.nist.gov/el/materials-and-structural-systems-division-73100/gsas-tutorial-rietveld-refinement

All the above web-site also include tutorials and learning material on Rietveld Analysis.

Hi,

Just to make sure I understood your question: do you want to subtract the "instrumental error" (?) or the "instrumental contribution to peak broadening"?

If it is possible to do annealing treatment of your material (to remove all the defect induced effects which contributes toward broadening), I would suggest you to do that rather than go for Si peak subtraction.

If you have to do with Si peaks only, then try to calculate the broadening of Si peak at your angle of interest (either by interpolation or by making a fitting function for the Si broadening wrt. 2theta). Then subtract the broadenings in accordance to the selected profile function (linear for Lorentz, sqr. for Gaussian etc.)

Mr. Grivel I want to subtract instrumental contribution to peak broadening.

Mr. Yadav annealing isn't possible now AND I have tried to do with both "interpolation" and "fitting function" methods. I was wondering which one would be better? . Interpolation will assume linear relation between two known points AND all points are not in a straight line. while fitting is done with power function(function fitting gives R^2=0.99 ).

I think no matter which method I follow (interpolation or fitting function) there will be some lack of accuracy always. Please share your views here. TIA

Rietveld refinement models the experimental XRD profile by accounting for the contribution of the instrument and of the crystalline phases present. You will need to know or measure some characteristcs of the instrument used that are used to calculate the instrument function -thus the contribution of the instrument to peak broadening, background and shape. You will also need a structure file for Si that is used to model the mineral contribution.

There are several software available for Rietveled, a few are open-source, here's a couple of my favorites:

Profex (BGMN): http://profex.doebelin.org/

FullProf: https://www.ill.eu/sites/fullprof/php/tutorials.html

GSAS: https://www.nist.gov/el/materials-and-structural-systems-division-73100/gsas-tutorial-rietveld-refinement

All the above web-site also include tutorials and learning material on Rietveld Analysis.

Debora Berti I am not sure how rietveld refinement will help me separate instrumental contribution of the instrument. I will try though. Thanks !!!

Yes its true, broadening not follows linear pattern. So, if you want to go fitting function, although power function are easy to perform for better accuracy you can increase the power or even go for some other function if they give a better fit.

You can also consider adding the lorentz polarization factor to the fitting function, as the broadening patterns largely depends upon it.

Hi Dragoe ,

Which broadening you are referring here?Is it instrumental braodening or sample peak broadening?