Hello Shivani, see the answer for your question in attached file.

Best reguards

Thanks Igor Kolodiy

Igor is right!

We "peal" them apart at any angle (low/high) in the reciprocal space using the X-ray Rocking Curve Method (aka Bragg XRD Microscopy).Example of Quartz Rocking curve with both K Alpha 1 & 2 present and separated:

http://www.flickr.com/photos/85210325@N04/7852409924/in/set-72157632724063041

In most X-ray rocking curve analyses the incident beam is absent the K Alpha 2 component and a very low inherent FWHM (instrumental). However, in the case of Quartz above, we actually turned "lemon to lemonade" by using the separation between the two topographs (K Alpha 1 & 2) to re-calibrate the Omega scale.

Obviously, the presence of two superimposed topographs may appear to be confusing but when viewed in the Omega space the individual topographs are easily deconvoluted. The inherent FWHM is at least an order of magnitude higher in this case compared with monchromated optics. But since the Quartz was of such high quality the peaks were amply well separated for deconvolution. Here the RCP profile shape was more akin to Pearson VII m=5: http://pd.chem.ucl.ac.uk/pdnn/peaks/pvii.htm

Here are some other examples of RCP shapes that we encountered:

http://www.flickr.com/photos/85210325@N04/8561945111/sizes/k/in/photostream/

Ravi

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