I have synthesized SnFe2O4 nanoparticles by coprecipitation method. Which should have same structure as Fe3O4. But the XRD result is surprising, it is showing that the highest intensive peak which should comes at around 35, comes at 23 degree. And the peak which should comes at around 30 , comes at 20 degree.
Can anyone help me to solve this problem? it is very urgent
@ Subhadeep Sen
Check whether any impurities are present in your sample. Also, check whether the phases are formed properly. Sometimes mixed phases can also be present which hinders the dominant peak.
B. Srikanth Ragunath THANKS FOR THE ANSWER. BUT THERE IS NO CHANCE FOR IMPURITY TO BE PRESENT IN THE NANOPARTICLES. AS WE HAVE SYNTHESIZED THIS NANOPARTICLE 5 TIMES AND ALL THE TIMES WE GOT THIS SAME TYPE OF XRD RESULT. SO AS YOU MENTIONED THE PHASES DID NOT FORMED PROPERLY OR MIXED PHASES MAY BE PRESENT THERE. SO CAN YOU TELL HOW TO KNOW ABOUT WHICH TYPES OF PHASES ARE FORMED THERE?
Dear Subhadeep Sen ,
your strong peaks look like peaks arising from quite large crystallites.
But for nanoparticles I expect broad*) peaks.
When carefully looking at about 35° there is a broad peak, but its peak height is small. This peak may arise from nanoparticles. If you expect that this (35°) peak should be much higher than your expected peak at 30°, you should not wonder when the 30°-one cannot be seen.
The yield of your chemical process seems to be poor.
Some of the prominent peaks, I think, arise from your ingradients.
You should check that...
*) in peak width
Good luck
Gerhard Martens Thank you so much for your valuable answer. I shall keep those words in mind while synthesis of nanoparticles.
Please open the below link of article (https://www.researchgate.net/publication/352830671or http://dx.doi.org/10.13140/RG.2.2.27720.65287) which practically explains the structures of different materials; structural analyses of different materials validate new atomic structures; study further discusses that crystalline materials do not require primitive cells in order to explain the structures and the distance between electronic states is relevant rather than the lattice constant; study reveals the preliminary detail of crystallinity, non-crystallinity, porosity, texture and noise factors along with overall characteristics of peaks; study further categorizes the residual and thermal stresses; shift in peak, hkl values, Miller Indices, planes, d-spacing, Bragg diffraction, Scherrer equation, pdf card are also explained in this study. Overall, the study suggests to re-investigate the materials at all scales. (This article is not peer reviewed yet.)
Hello,
It is clear from the image that the diffraction pattern contains only a small amount of nanoparticles. However, the pattern needs to be evaluated qualitatively. If you add raw (raw file, dat or x-y etc.) data from measurements here, then we can try to evaluate. From the picture, it's extremely difficult. Apparently unreacted substances predominate.
The record was easily evaluated from the supplied raw file with using the PDF database. The sample contains phase, which is close to Jeanbandyite. This is FeSnO(OH)5O, respectively Fe3+xFe2+1-xSn(OH)6-xOx. This phase is cubic, space group Pn-3:2 (201) (special settings in this group).
The cell parameter came to (full profile fitting, Pawley method ) a = 7.64306(14) Angstr., the diffraction domain size (Lorenz) is 105.7(15) nm.
Dalibor Matýsek thank you sir , this information will be very helpful to me.
It is also possible to add the result of Rietvetveld refinement from the Topas program. It is only very indicative, because the program uses a fundamental parameter approach and of course I do not know the settings from the used goniometer. However, the results confirm the above phase.
unit cell from Rietveld refinement is 7.64313(16) Angstr., and domain size is 107.4(18).
Dalibor Matýsek thank you so much sir for those valuable information.
Dear Subhadeep Sen, as per our communication, the major phase is FeSnO(OH)5 as Dalibor Matýsek mentioned and a small amount of nano Fe3O4 like structure, however, there is a foreign peak at 80.79 which has a different profile. I can't find it in my database. Perhaps someone can give a solution.
Dear Maykel Manawan and others,
Yes, I know about the excess peak of 80.79o 2 theta, as well as observing traces of the spinelide phase. The peak at 80.79o is extremely difficult to evaluate, as any other peaks are missing for possible impurities. This is too small interlayer distance to be the main peak of the single phase (approx. 1,188 Angst.). Jeanbandyite belongs to the group of perovskites. Different structural deviations, modulated structures, etc. are possible for them. It is necessary to consider whether this cannot be this case. I would also like to point out that the diffraction pattern that is available very likely also contain an amorphous component and not in small quantities.
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