Editing X-ray scattering techniques

{{Short description|Family of non-destructive analytical techniques}}
[[Image:X-ray diffraction pattern 3clpro.jpg|thumb|250px|This is an X-ray diffraction pattern formed when X-rays are focused on a crystalline material, in this case a protein. Each dot, called a reflection, forms from the coherent interference of scattered X-rays passing through the crystal.]]
'''X-ray scattering techniques''' are a family of analytical [[scientific technique|techniques]] which reveal information about the [[crystal structure]], chemical composition, and physical properties of materials and thin films. These techniques are based on observing the [[scattering|scattered]] [[Intensity (physics)|intensity]] of an [[X-ray]] beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.

Note that [[X-ray diffraction]] is sometimes considered a sub-set of X-ray scattering, where the scattering is elastic and the scattering object is crystalline, so that the resulting pattern contains sharp spots analyzed by [[X-ray crystallography]] (as in the Figure). However, both [[scattering]] and [[diffraction]] are related general phenomena and the distinction has not always existed.  Thus [[Guinier]]'s classic text<ref>{{cite book|last1=Guinier|first1=A.|title=X-ray diffraction in Crystals, Imperfect Crystals and Amorphous Bodies|date=1963|publisher=W.H. Freeman & Co|location=San Francisco}}</ref> from 1963 is titled "X-ray diffraction in Crystals, Imperfect Crystals and Amorphous Bodies" so 'diffraction' was clearly not restricted to crystals at that time.

==Scattering techniques==

===Elastic scattering===
* [[X-ray diffraction]], sometimes called Wide-angle X-ray diffraction (WAXD)
* [[Small-angle X-ray scattering]] (SAXS) probes structure in the nanometer to micrometer range by measuring scattering intensity at scattering angles 2θ close to 0°.
* [[X-ray reflectivity]] is an analytical technique for determining thickness, roughness, and density of single layer and multilayer thin films.
* [[Wide-angle X-ray scattering]] (WAXS), a technique concentrating on scattering angles 2θ larger than 5°.

[[File:Schematic IXS spectrum.png|thumb|upright=1.25|Spectrum of various inelastic scattering processes that can be probed with inelastic X-ray scattering (IXS).]]
===Inelastic X-ray scattering (IXS)===
In IXS the energy and angle of [[inelastic collision|inelastically]] scattered X-rays are monitored, giving the dynamic [[structure factor]] <math> S(\mathbf{q},\omega)</math>.  From this many properties of materials can be obtained, the specific property depending on the scale of the energy transfer. The table below, listing techniques, is adapted from.<ref>{{cite arXiv|eprint=1504.01098|last1=Baron|first1=Alfred Q. R|title=Introduction to High-Resolution Inelastic X-Ray Scattering|class=cond-mat.mtrl-sci|year=2015}}</ref> Inelastically scattered X-rays have intermediate phases and so in principle are not useful for [[X-ray crystallography]]. In practice X-rays with small energy transfers are included with the diffraction spots due to elastic scattering, and X-rays with large energy transfers contribute to the background noise in the diffraction pattern.
{| class="wikitable"
|-
! Technique !! Typical Incident Energy, keV !! Energy transfer range, eV!! Information on:
|-
| [[Compton scattering]] || 100 || 1,000 || Fermi Surface Shape
|-
| [[Resonant inelastic X-ray scattering|Resonant IXS]] (RIXS) || 4-20 || 0.1 - 50 || Electronic Structure & Excitations
|-
| Non-Resonant IXS (NRIXS) || 10 || 0.1 - 10 || Electronic Structure & Excitations
|-
| [[X-ray Raman scattering]]|| 10 || 50 - 1000 || Absorption Edge Structure, Bonding, Valence
|-
| High resolution IXS || 10 || 0.001 - 0.1 || Atomic Dynamics, Phonon Dispersion
|}
* 

== See also ==
{{div col|colwidth=22em}}
* [[Anomalous scattering]]
* [[Anomalous X-ray scattering]]
* [[Backscatter]]
* [[Materials science]]
* [[Metallurgy]]
* [[Mineralogy]]
* [[Rachinger correction]]
* [[Structure determination]]
* [[Ultrafast x-ray]]
* [[X-rays]]
* [[X-ray generator]]
{{div col end}}

==References==
{{Reflist}}

==External links==
{{commons category|X-ray diffraction}}
* [http://www.xtal.iqfr.csic.es/Cristalografia/index-en.html Learning Crystallography]
* [http://www.iucr.ac.uk/ International Union of Crystallography]
* [https://web.archive.org/web/20070405181230/http://www.iucr.org/cww-top/crystal.index.html IUCr Crystallography Online]
* [http://www.icdd.com/ The International Centre for Diffraction Data (ICDD)]
* [http://crystallography.org.uk/ The British Crystallographic Association]
* [http://www.mrl.ucsb.edu/centralfacilities/x-ray/basics Introduction to X-ray Diffraction] at [[University of California, Santa Barbara]]

[[Category:Laboratory techniques in condensed matter physics]]
[[Category:X-ray crystallography]]
[[Category:Materials science]]
[[Category:X-ray scattering]]