The structure of the Nax(Ni,Mn,Co)O2 phases is well known. Change of the Ni:Co:Mn ratio will lead only to the minor modification of the peak intensities, which will be almost undetectable by the laboratory XRD. In order to check the purity of the phase compare your diffraction data with any similar entry from the database. If you need more detailed data, take any comparable structure, set the necessary Ni:Co:Mn ratio and perform the Rietveld refinement.

I think that you already predict the type of this material, for example if you are looking for oxyphosphate you can search in litterature the materials corresponding to oxyphosphates and you can make a comparison.

Thank you Noha Sabi for your comments. However can you make it more clear on your explanation, being specific to my case..I am synthesizing NaxNiMnCoO2 but the ratio of Ni, Mn and Co is different. In such case the XRD peaks will also be different. 

The structure of the Nax(Ni,Mn,Co)O2 phases is well known. Change of the Ni:Co:Mn ratio will lead only to the minor modification of the peak intensities, which will be almost undetectable by the laboratory XRD. In order to check the purity of the phase compare your diffraction data with any similar entry from the database. If you need more detailed data, take any comparable structure, set the necessary Ni:Co:Mn ratio and perform the Rietveld refinement.

Totally agree with Alexander. Go with Rietveld refinement. May be Raman is helpful.

Dear Vivek Tiwari

You can also obtain some information from XPS, FT-IR, UV-vis DRS, and PL spectroscopy.

Thank you all Respected Researchers for the suggestion. I will learn about Rietveld refinement, seems complicated process for the begineer . However how about using EDS result of wt% to estimate the formation of desired compound ? I read in some papers using ICP-OES for confirming the compound synthesis. Do you think EDS wt % is also a good option at the early stage to confirm? 

If the XRD patterns of Nax(Ni,Mn,Co)O2 phases are similar (just minor peak shift in XRD pattern) with that of the well known NaMO2 layered structure , then you can do the Rietveld refinement to get the structure information. I suggest the Rietveld software  MAUD for beginner. 

I think that recommendations given above are quite sufficient for solving the problem. I just coincide with them/ Do read any modern textbook on X-ray analysis.

If Na is x which other metal you want to replace...i mean NaxNi1-xMnCoO2 or what?... whichever you want, as Mr Yin wrote, the general structure would be NaMO2...this structure might have xrd database if they are crystalline always (without annealing/sintering)...

Dear Vivek,

                   My suggestion is to check EDX pattern on different positions of the sample.  then search with the jcpds file for the edx resulted composition. May be helpful to find out the exact proportion that actually formed in the process. 

Another possibility is formation of composite; check for xrd peaks of different possible composites that can be formed from the precursor. This suits for many cases.

Thank you Researchers for all the suggestions. 

Hello Dr. Gokul Raja, I thought initally with EDX but  later i came to know EDX won't detect the lighter elements (Atomic No< 11) efficiently. So i think Oxygen can't be detected proportionately. Thus EDX may not be the good option. Do you agree?

If you need the exact oxygen content, the best technique is ox-red titration. There are several protocols, but all of them are based on the reduction of all transition metals to +2 oxidation state. Search the literature and choose the one which is more convenient for you.

Hello Dr. Missyul thank you for your regular suggestions. I really appreciate that. I just wanted Phase Purity. I am not in to finding exact oxygen content , i was thinking of EDX  because of my familiarity with the application only. As per your suggestion in previous comment about Rietveld Analysis and i am planning to change the ratio Ni, Co, Mn in the software and perform RA .  I am using MAUD software for RA.

Hello Dr. Mishra, 

Yes there is XRD structure for this compound Na0.6667 (Co0.0417 Ni0.2916 Mn0.6667) O2 . Which will also have a layered structure. 

Hi Vivek,

               I agree the fact that "EDX won't detect lighter elements". But, the limit is nearer to Atomic number 6. Analysis of the elements below atomic number 6 was only can't be done with EDX. I had took EDX of ZnO, F-doped oxides, which resulted in clear percentage of that elements also. you can refer my published article here. 

Kindly ask the EDX technicial of your workplace about the lower atomic number elements and their detecting capability of the machine. Best wishes