First of all, you need to know which possible phases do you expect. Each crystalline phase contributes to "2Theta-Intensity" spectrum its own characteristic group of reflections (peaks), while each reflection corresponds to certain group of lattice surfaces (hkl). For each certain crystalline phase, reflections' 2Theta and relative intensity are crystallographically defined. Then you need to identify each of the obtained peaks in your spectrum and to relate them to certain crystalline phases. The amorphous phase contributes only a halo (not peak).

Let consider a situation that you have only two phases: rhombohedral and amorphous graphite. Then you should select the strongest ("representative") peak of the crystalline phase and to compare its integral intensity ("area") with that of the amorphous halo (area under the halo) which represents the amorphous phase. The ratio between these two areas is the ratio between the crystalline and amorphous constituents in your analyzed blend.

Anyway, I recommend, for beginning, to read a basic literature in XRD, for example, the book Gullity "Fundamentals of X-rays diffraction". After that, you can perform a literature survey to find exact description of this quantitative analysis procedure.

Can you attach the pcr file? Finding of the problems may be easier from the pcr file.

Thank you for your advising. I attached the *.pcr file that I prepared. I have used an internal crystalline standard to determine the amount of crystalline and amorphous phases.

@ Alexander Katz-Demyanetz : First of all, I want recommend to use diffractogram instead of spectrum. Also lattice surface is a quite unusual term. I guess you are talking about lattice planes? Util now I've never heard that the strongest reflection related to the amorphous halo (area under the halo?) gives you the ratio between crystalline and amorphous fraction. Do you have any reference?

In general, the agreement of only one small peak with a rhombohedral phase...whereas no other predicted position shows any intensity in your diffractogram, isn't this a bit too speculative? How do you explain all other missing reflections?

The strange peak shape indicates (from my limited point of view) the existence of disordering e.g. a turbostratic stacking. This generates extremely asymmetric peak profiles. I would suggest to check papers reporting about similar effects in clay materials. At least I have seen such effects mainly there.

@ Bayanjargal: The .pcr file which you attached is very old (01/07/2018) and unrefined i.e. refined is not performed by the attached .pcr file. So, I advise you to create a new .pcr file for 1st phase and perform Le-bail fit and then add 2nd phase and perform Le-bail fit for 2nd phase. After that go for Rietveld refinement for 1st phase and then 2nd phase. I hope, it will wok.

@ D. Kumar: It might be necessary to explain shortly what the Le Bail fit is doing and why do you recommend it. And please consider that the term contains the name of the scientist who introduced this technique: Armel Le Bail.

@ G. Nolze & Bayanjargal: I know the scientist who introduces the method for profile fitting of XRD data without providing any information about atomic arrangement. I am recommending this before performing final Rietveld refinement because if we perform this then we have to only refine the coordinates of the atoms and we can identify the error in the coordinate refinement.

https://link.springer.com/content/pdf/10.1007/BF00557189.pdf

http://www.x-raywizards.com/Services/Percent_Xtal/Application_Note_P01-crystallinity-PE.pdf

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=5724069

https://ac.els-cdn.com/S0960852410001549/1-s2.0-S0960852410001549-main.pdf?_tid=d7983b43-4ac0-48c4-b4e9-1d78092539b0&acdnat=1538634383_caa51dca4bd99090f3b26b71a171adef

@ D. Kumar: My remark was diercted to explain this in more detail to B. Erdenee. It might be that he does not understand why do you recommend this. And regarding the name: I wanted to point out that your "Le-bail fit" is correctly a "Le Bail fit". Since you wrote two times "Le-bail" I wanted prevent any misleading regarding other readers.

Anyway: Could you please explain what you just said: "... if we perform this then we have to only refine the coordinates of the atoms and we can identify the error in the coordinate refinement."?

I mean, what a Le Bail fit really does? And what do you still want refine except of the structure B. Erdenee is interested in?

@ G. Nolze: Yes, I know that the name of scientist (noun) is always written following first letter in capital. It is a technical method which is often written as "Lebail fitting or Le-bail fit". One can see the screenshot of manual of FullProf Suite attached below.

@ Bayanjargal: For more details about Lebail fitting you can follow the references given in the attachment.

Regards

D. Kumar

Only since it has been written or printed somewhere wrong does not make it correct. You also find "Rietfeld" or "Reitveld" or "rietveld" but all these terms are simply a wrong spelling of a name.

Nevertheless, I am still not entirely sure why do you recommend a LeBail fitting. In other words, do you really think a LeBail fitting would improve the match shown above?

Thank you for advising me. I have studied several kinds of literature that indicates how to describe the structure of graphite.

I have a question again, what are Shi model and CARBON XS program?. Where can I find this program and its tutorial?.

Here found a additional tool, find the attachment.