Hi.

If you don't know your cell parameters, you can try indexing programs like Dicvol or McMaille (http://www.cristal.org/McMaille/McMaille-v4.html).

There are other softwares that you can check here : http://www.ccp14.ac.uk/solution/indexing/

You can also have a look in the free Crystallographic Open Database (http://www.crystallography.net/).

Regards

Ms. Lita, If I may assume what you are asking is that you found a peak(s) that cant be identified by JCPDS.

If that so, you might try to make sure that the peak doesn't come from your substrate or other impurity(ies).

Please provide the data and your JCPDS# if you dont mind.

Dear Mr Firman

in my case, there are not JCPDS card because i synthesized graphene. and i don't know how to measure the hkl index

In UTEM,u can done the analysis and it will give u the report in excel all of that.

Oh,im sorry.you not study in malaysia.so,you can downloadbone software called match and the saved data u have u can open there, and u can find the hkl bybperform the analysis using the software.

Hi.

If you don't know your cell parameters, you can try indexing programs like Dicvol or McMaille (http://www.cristal.org/McMaille/McMaille-v4.html).

There are other softwares that you can check here : http://www.ccp14.ac.uk/solution/indexing/

You can also have a look in the free Crystallographic Open Database (http://www.crystallography.net/).

Regards

There are many possibility to discover the Miller index. For this it is necessary to know firstly the crystallization system. Try to use Hull diagrams.

Jcpds

I agree with Firman Mangaza

Dear Lita. You can determine hkl to cubic structures from some rules selections. Each peack have an tetha angle of diffraction. The relationship between cell parameter of cubic structure and interplanar distance is a = d/(h^2+k^2+l^2)^0,5. Now, consider the Bragg´s Law: lambda = 2dsintheta. Insert an equation in another as obtaining a linear relation where (lambda)^2/4a^2 is the angular coefficient . If your structure is cubic, so you can find hkl parameters. 1. Take de sin^2teta; 2. Normalize, i.e., divide the sin^2teta by the minor value; 3. Multiply each value by a same namber in order you obtaining integer numbers. This integer numbers is the suma of hkl parameters. If suma hkl is odd or even your structure can be primitive cubic, Body-centered cubic or Face-centered cubic.

As Jones said..determining h,k,l for cubic system is easy but for other systems it is very difficult.And I think you don't know which system it is too...

If you are truly making graphene, or graphene oxide, these are primarily 2-dimensional planar structures that may (or may not) have long-range order in the dimension normal to the planes. Suggest you look in the literature for x-ray structure analysis on GO. For example:

http://pubs.rsc.org/en/content/articlelanding/2013/nr/c3nr04631a#!divAbstract

I completely agree with Payzant. Try searching literature. What machine did you use to get the spectrum? If it's truely two-dimensional, you should see nothing - or close to nothing - with a conventional diffractometer. What is your scanning range? If you are trying to differentiate between graphite oxide and graphene oxide, that is an important factor.

I agree with Edward Payzant.

I am not sure if you can get XRD signals from pristine graphene, which is the truly 2D crystal, without any (002) stacking. However, I tried to get (100) and (110) signal from CVD graphene, I could not find any significant diffraction peak from it, because it is too thin. Many literatures show broad XRD (002) peak on "graphene", personally I don't think they are true 2D crystal graphene, it could be unexfoliated nano-graphite particles. Noteworthy that these samples are highly inhomogeneous from top-down liquid phase exfoliation, some nano-graphite particles could be contained in the powder. 

Use the Bragg relation and test various values of Miller index (hkl) til this relation is satisfied. Other method is to use Hull diagrams. Success!

Each material has JCPDS card existing the standard peak positions with the hkl index. From which one can index the peak.

Perhaps, the question was ambiguous. However, one can determine the hkl index with helping XRD software like Xpert's High Score, Match softwar. These are online free software.

Generally, Xpert's High Score (version 4.8) , a powerful tool, was suggested to analyse the XRD spectra of materials. This software (by aid of PDF 2 and PDF 4 ICDD cards) helps researchers to fully analyze and study the crystalline structure of materials. It will be possible to easily obtain the miller indices(hkl) related to each crystal planes (JCPDS card) with this software.

You need to find inter plane separation distance, d from very low dimensional plane say (004); then depending on the crystalline structure relationship with d, lattice constant a, you can find h,k, l value.

First you have to measure very accurate, higher order plane say, 004 plane XRD. From the result you have to find d. For particular cubic materials you know lattice constant, a. or hexagonal materials, c is required. From measured d and calculated either a or c you can find h, k and l values by using specific formulas.

Please read crystallographic book and carefully solved the exercise. hope you can do yourself.