There are different strategies to interpret the XRD data of the compounds synthesized in the laboratories. You have to first check that the compound you are claiming is really a new compound or not. This can be tested by the qualitative analysis of your compound. You have to compare XRD pattern of your unknown compound with the XRD (JCPDS) pattern of the compounds those are used in the synthesis, or the possible compounds of the precursors used in the synthesis. for example if you are using co-ppt method for oxide formation you have to also check the hydroxide phase formation.

Once you confirm that your compound is brand new and is not reported earlier, kindly find the chemical composition of it. Then you index your XRD data based on the reflections. This can be easily done with help of EXPO-2011 software available free of cost from University of Bari.... In this software indexing packages like treor are embedded. All the lines should be indexed. Based on indexing results you can proceed for space group determination and later on you can solve the crystal structure using EXPO (Direct space method or the other). The resulting model you can refine using rietveld refinement softwares to complete the structures. If you can elaborate little bit about your systems then only we can advise you in more detail..

Powder XRD software's like X-Powder and MDI JADE 6 have the option of search and match. They analyse your XRD pattern, identify the peaks and match with the database for already existing XRD patterns of a number of chemicals.

OK, Thanx to all ...first I will try this much.

First be sure you don´t have ANY artifact like special orientation etc. I can only recommend you first to intensively characterize your compound with spectroscopy before you go further. THEN this is a daring but interesting task - I would recommend you the FOX package because it uses much chemical information. You need before to have an estimate from the the space cell, use for this something like McMaille and estimate a of the space group.

Get a software for XRD analysis such as "Jade5". Install the PDF database (JCPDS). After searching peaks, smoothing and so on, match your pattern with the database. The results may give you some suggestions.

Hello Sachin..I downloaded FP software..got winploter also,but my data is in .MDI format.How should I proceed further.

You can download the CONVX software for conversion of data.....from one format to another..... if you permit we can help in the analysis if you are beginner in the XRD data interpretation....

Thanx a lot Sachin and D.S.Bhange Sir.

As Alexandre Mantion said, be especially careful with the sample preparation for the XRD measurement. For correct structure determination from powder data it is crucial to have accurate intensities/statistics. The book "Structure determination from powder diffraction data" (IUCr) gives a good overview on this subject

Ok Alfred Sir

hi richa,

i m not expert in this XRD. but let me understand some points frm ur question.

1) are u sure phase is formed in ur sample and then u r trying to understand the structure?

2) what do u mean by new XRD? i mean how do u know it was new? did u check the individual component XRD and check with ur new XRD pattern?

Refinement of structures will be done once u fixed some space group of particular structure.if not refinements are laborious work. but first find out whether phase is formed or not.

Yes Venkat Sir, new phase is formed because the pattern i m getting is different from the starting material and as i m increasing the temperature pattern is changing.

hi,

xrd changes when temp is increasing. did u observe pattern no: of peaks decresing at high temp or any splitting at lower temperatures is not observed at high temp xrd. since u are telling pattern is changing with temperature(only when particular structure is formed) it may be changed from lower symmetry crystal structure to higher stable symmetry structure. more number of xrd peak is in ur system it implies that system gone into lower symmetry(just a guessfor next step). eg (100) has (010),(001),(100) and their negatives represents single peak in cubic XRD but not in orthorhombic where lattice parameters are diff.

above explanation u may know already but be sure ur single phase if not every step into XRD gives wrong intrepretation. if opposite happens then think about the possible other phases in the system.

first get the possible stoichiometric formula for ur sample. check the possible structures possible previously for that compound. eg. ABO3 type most possible at room temp are orthorhombic or rhombohedral (as my knowledge was concerned). most of the compounds will not deviate much from the parent structure. have a fun by checking same space group(eg Pnma of orthorhombic) of different compounds (keep an eye with lattice parametr variation) from JCPDS.

Thank you Venkat Sir...will try to come to a conclusion keeping all aspects in mind.

What do you mean Unknown composition....

If it is synthetic.. You should know the chemical moieties present in it..(which elements are present both qualitatively and as quantitatively)

May be you want to say unknown phase of known chemical composition

In any case you need an estimate about the contributing atoms - otherwise it is laborious to get a structure solved. Look at a textbook for peak indexing procedures, and try educational pages for XRD (look at RG-pages or search the Web). In part this is learning and exercising! Good luck, Dirk

Ya..I am trying Dirk Sir...

Hi Richa mam

What software are you using for XRD Analysis?

Richa - the question is, whether or not did you succeeded with your problem! Please keep us updated! Kind regards, Dirk

Hello Dirk Luetzenkirchen- Hecht Sir...... Many Thanx for ur concern Sir.... To some extent I am successful...not completely..... But I got the basic logic how to do it.....so i m trying....