See this RG discussion regarding the real time 2D XRD rocking curve analyses of the NIST 2000 SRM and other very interesting materials! Also check out the YouTube video "Playlist" attached!

XRD Rocking Curve Analysis, nearly a century aged powerful technique, is the quantification of the deviation from IDEAL BRAGG CONDITION! This deviation may then be related back to the Nano structure of each VOXEL on the sampling surface. Also termed as Bragg XRD Microscopy or XRD Reciprocal Space Microscopy :-) The Nano structural strain sensitivity is in the FEMTOMETER range with this technique. 

XRD rocking curve analyses include Omega Scan, Omega-2Theta scan, 2Theta (?) scan, Chi scan & Phi scan. It appears that there is no standard nomenclature yet as most users are still stuck with the debilitating archaic "spatially blind" 0D point counter or a slightly more advanced 1D (LPSD) detector. This inhibits the ability to visualize and correlate to spatial Nano structure. It would be time prohibitive to use such ancient technology to map the Nano structure of the sampled surface (wafer). Been there done that @ RU 1980's. In fact, ancient (nearly extinct) photographic film turned out to be a better alternative then. I bet you folks don't have such paraphernalia in your XRD labs :-)

Do add up to 15 relevant topics up top for enhanced exposure and participation from the "expert" RG membership. What material systems are of interest to you?

BTW I was schooled in the art of XRD rocking curve analysis by Sigmund Weissmann of Rutgers who had the privilege of the tutelage of the younger Bragg. There are numerous publications from Weissmann et al on this subject since the 1950's :-)

https://www.researchgate.net/post/What_is_the_best_way_to_interpret_REAL_TIME_3D_X_Y_Omega_2Theta_reciprocal_space_relative_intensity_data_from_HRXRD_rocking_curve_analyses

https://www.youtube.com/watch?v=dFCQS8oUyT0&index=37&list=PL7032E2DAF1F3941F

The rocking curve is a way to explore a small region of reciprocal space at a constant Q-value. This is the only way to get information about the missorientation of different domains or zones of the film/crystal.

I try to explain this with an example. If you collect a theta/2theta scan you will find diffraction peaks corresponding to the family of planes parallel to the surface. This scan corresponds to a travel in the reciprocal space in the direction perpendicular to the surface. For example, in a cubic/tetragonal/orthorhombic cell, and a (001) surface, the travel will be along (001)*. For every point in the scan the modulus of Q will be 2sin theta/lambda. In general peaks will be thin (for very thin films, they will be wide due to the finite size effect). With this technique one can detect only interplanar distances, and that there are regions of the crystal with the right orientation (parallel to sample surface). To detect different orientations of those planes it is mandatory to make scans conserving the value of the Q modulus. There are different ways to perform that and one of those is a rocking curve. Moving omega keeping 2theta fix makes a travel in the reciprocal space that is a circumference around the ideal position of the diffraction peak. How quickly it disappears the intensity around this ideal position of the peak inform you about how disperse is the orientation of the corresponding planes: a rapid drop of the intensity means small dispersion, and a slow drop a large dispersion. To compare, if you have a polycrystalline sample (every possible orientation of the planes is present), there will be no variation of the intensity along the curve (the only variation will be due to geometrical reasons).

"rocking curves in XRD analysis" - A method to quantify deviation from ideal Bragg condition.

https://www.flickr.com/photos/85210325@N04/11604959265/in/album-72157645018820696/

thanks for nice comments.

Is it necessary to perform in a HRXRD or it can be performed either in a "conventional" XRD? 

Thanks in advance

Yes! It is possible to use incident beams conditioned by various means for rocking curve analysis.

In principle, the measured rocking curve profiles need to be normalized w.r.t. the "strain free" rocking curve profile simulated through LEPTOS or other numerically tools. At the time of such simulation, the input parameters need to include those characterized by "HRXRD" or  "conventional" (depending on what you mean:-). It is possible and helpful to compare observed values to some sort of a 'standard sample' as well.

Ideally, one would want a "delta function" for the incident beam. This would be only possible with a synchrotron. Most other laboratory based diffractometers would have a specific wavelength distribution, termed as "instrumental profile". This "instrumental profile" would depend on beam conditioners used in the diffractometer.

Temporal, spatial and reciprocal space resolution are dramatically affected by the incident beam characteristics. The HRXRD typically uses Cu K Alpha 1. The "conventional" XRD as you have termed it, would generally include the convolution of both Cu K Alpha 1 & 2 components (higher signal levels). The information present in both cases contains the Nano structural signature of the sample crystal. With advanced analyses tools if is possible to deconvolute the information of interest.

Example below for both may help the understanding of the concept better:

1. Rocking curve with K Alpha 1 & 2 for a quartz crystal: https://www.flickr.com/photos/85210325@N04/7852412540/in/photostream/

2. Rocking curve with K Alpha 1 only for ZnSe wafer: https://www.flickr.com/photos/85210325@N04/7916092350/in/photostream/

https://www.flickr.com/photos/85210325@N04/7916092350/in/photostream/

By analyzing rocking curves of various reflections it is possible to deconvolute the contribution of various types of defects present in the sampling voxel at the wafer surface.

https://www.youtube.com/watch?v=kGQb8EiSQAw

https://www.youtube.com/watch?v=lwVPe25wGJI

Can someone explain the out of plane, in-plane and reciprocal space mapping techniques for III-V epitaxial films through XRD measurements?

Requiring the basic distinctions between each, right from instrument set up towards data analysis?

To get a sustainable solution to your problem, please refer to the preprint article given at link DOI: 10.13140/RG.2.2.27720.65287/3 or at link https://www.researchgate.net/publication/352830671.