Dear Mahboobeh Rezaeeyazdi

The first step would be to verify that the sample holder was not contaminated; the following, check that the peaks do not belong to pure substances used in the reaction.

Did you found a new substance!?

Best regards

Carlos

Carlos Ariel Samudio Pérez

Thank you for your time and answer. The peaks definitely don't belong to the sentences.

My limited knowledge of XRD says that if you are finding two random peaks, it's most probably contamination not another substance since every substance comes with several of peaks not just two peaks, I'm not sure if I'm right though.

Take in account the sample holder used: if the sample used for the XRD analysis is thin it is likely that the additional lines belong to the sample holder material.

Please check for k beta or W L alfa radiation

I recommend the use of X'pert HighScore software to identify unknown peaks and to check in parallel the purity or not of this reaction sample.

best regards

Mrs. Achour.

Hi dear Mahboobeh Rezaeeyazdi

Would you share your XRD pattern photo with us?

Then we can help you better.

Regards

There are several tools that allow you to optimize the results in phase identification by XRD. Normally it is not necessary to use special methods, but in some cases surprising results can be obtained. In really complicated cases (poor quality of diffractograms, serious problems of orientation preference, isomorphic phases with infrequent cells, errors (linear or non-linear) in the 2-theta registers, etc. some small tricks can be used. Among them I recommend, to example mode

1. Use a database whose angular intervals are similar to those of our laboratory.

2. Use periodic systems of elements that do not contain elements foreign to the usual ones. For example, I usually use periodic systems that frequently contain a maximum of the 15-20 most probable elements.

3. Assist the identification program with any auxiliary information (for example, filter the results by visible and / or ultraviolet color of the analyzed powder).

4. Of course it is necessary that your database contains the phase you are trying to identify. Otherwise, you can calculate all possible theoretical diffractograms using COD's crystal structure database, to include they in your Powder X-Ray Diffraction Database.

5. Consider that a minority phase or very oriented in a mixture of phases, can present very few reflections and even very weak. In this sense, it is convenient to control the homogeneity or not of each and every one of the reflections of the diffractogram. Minority and / or low crystalline phases will give broad peaks compared to more crystalline phases. This is an additional identification criterion. 6. If you have a well-identified pattern of sufficient quality in the mix (for example quartz), do not hesitate to correct the 2-theta angles. Whenever possible, this correction should be non-linear. 7. If your program can perform the removal of the K-alpha component (K-alpha 2 stripping), feel free to do so. My experience tells me that you can increase a decimal when calculating the spacing. This is especially useful when the same program can comfortably calculate the unit-cell, which also helps in identifying the phases (particularly when they are part of a solid solution). 8. You can use additional logic listeners regarding chemical composition. For example you can use to identify only the most common carbonates in a mineral mixture: "(C and O) and (Ca or Mg or Zn or Ba)". Or frequent hydrate carbonates: "(C and O and H) and (Ca or Mg or Zn or Ba)" On the other hand, I personally use the XPowderX program, which includes all the operations indicated above, but simply because I needed to program them for my own use because commercial programs do not contemplate these possibilities. There are many other tricks to obtain plausible results, but they usually depend on the personal experience of each researcher. In any case, if the crystalline material being analyzed is really interesting, correct conclusions are usually obtained despite the experimental difficulties. It is usually only necessary to have adequate time to find each solution (a few minutes or several months ... chi lo sa !!!).

Hello Daniel,

was the powder finely ground? You may try to re-mount the sample and collect another pattern. If you are laky perhaps those 2 little peaks will disappear.

This of course, is the solution number zero!

Please refer below links of the given entitled article to get some relevant feedback. Kindly note that the article is not peer reviewed yet.

Qualitative Analyses of Thin Film-Based Materials Validating New Structures of Atoms. (2021), https://www.researchgate.net/publication/352830671or http://dx.doi.org/10.13140/RG.2.2.27720.65287

In X-ray analysis, changing GIA can help to understand the material’s properties in a broader perspective. From the characteristics of peaks resulted in pattern, we can get some idea about the texture of deposited/processed/synthesized material, but within the surface area dealt with the exposure of X-rays. However, by changing the position of sample and under repeated X-ray analysis, it is possible to draw the picture of texture in broader context. To study texture coefficient for a particular material, the development of a master pattern is necessary, which can be the reference pattern.

You may take the X-ray pattern of your sample by changing the GIA, i.e., 0.1 deg., 0.3 deg., 0.5 deg., 0.7 deg., 0.9 deg. you will see in the resulted pattern different scans of your same sample. In this way, you can explain the different factors related to structure of your material. At low GIA (0.1 deg.), you may get less peaks and less complicated/complex pattern, but at high GIA (0.9 deg.), you may get more peaks and more complicated/complex pattern. Please read the article to get better know how (https://www.researchgate.net/publication/352830671or http://dx.doi.org/10.13140/RG.2.2.27720.65287). Good luck!

Simply increase the glazing incidence angle (GIA), if the provision is available with the X-ray Technique/instrument.You may take the X-ray pattern of your sample by changing the GIA, i.e., 0.1 deg., 0.3 deg., 0.5 deg., 0.7 deg., 0.9 deg. you will see in the resulted pattern different scans of your same sample. In this way, you can explain the different factors related to structure of your material. At low GIA (0.1 deg.), you may get less peaks and less complicated/complex pattern, but at high GIA (0.9 deg.), you may get more peaks and more complicated/complex pattern. Please read the article to get better know how (https://www.researchgate.net/publication/352830671or http://dx.doi.org/10.13140/RG.2.2.27720.65287). Good Luck!

Well, XRD is preferred for structural verification. With only information about one peak at a certain position, you can do nothing. Perhaps, there could be another element or just a different phase of your material. You must have some idea about the origin of your observation and then for instance chemical analysis would be the better approach.

The foremost thing is how to avoid from unknown peaks in the pattern. Please make the possible efforts to synthesize the material under the controlled parameters. Under controlled parameters and atomically flat surface, the unwanted peaks can be avoided. (Please check the preprint article given at link http://dx.doi.org/10.13140/RG.2.2.27720.65287 explaining that XRD technique is, in fact, XRR technique.) The associated unknown peaks with the main peaks are also related to your material having the same composition of atoms, but the issue is that X-rays interacting with the atomic electrons having different positions, so the intensities of the interacting X-rays print at the different positions of detector with different angles of reflections. From front-side of top-layered surface, electrons of different-positioned atoms in your materials deal with the interacting X-rays in very different ways. This also indicates that the degree of crystallinity in the material is low. As a result, your pattern becomes complex. To avoid from it, you may use the GIA (glazing incidence angle) if the provision is found with the X-ray reflectometer (not diffractometer). If not, please synthesize, develop, or process your materials under controlled parameters, so that you will succeed to have the surface of your sample atomically-flat. If you are still not succeeding, you need to explain the causes. The atoms at different positions may deal with different behaviors, and for this, you can study another preprint article given at link https://doi.org/10.21203/rs.3.rs-88120/v2. This preprint article is related to atomic structure and different transitional states of the atoms.

For further information and to get the answer of your additional questions, please read the mentioned articles and conceive the concept in your own style. This will also work for the long term.