Editing Wide-angle X-ray scattering (section)

==Applications==
The WAXS technique is used to determine the degree of [[crystallinity]] of [[polymer]] samples.<ref>{{Cite journal|last=Murthy|first=N. S.|last2=Minor|first2=H.|date=1990-06-01|title=General procedure for evaluating amorphous scattering and crystallinity from X-ray diffraction scans of semicrystalline polymers|journal=Polymer|volume=31|issue=6|pages=996–1002|doi=10.1016/0032-3861(90)90243-R|issn=0032-3861}}</ref> It can also be used to determine the chemical composition or phase composition of a film, the texture of a [[Thin film|film]] (preferred alignment of crystallites), the crystallite size and presence of film [[Stress (mechanics)|stress]]. As with other diffraction methods, the sample is scanned in a wide-angle X-ray [[goniometer]], and the scattering intensity is plotted as a function of the 2θ angle. 

X-ray diffraction is a non destructive method of characterization of solid materials. When X-rays are directed at solids they scatter in predictable patterns based on the internal structure of the solid. A crystalline solid consists of regularly spaced atoms (electrons) that can be described by imaginary planes. The distance between these planes is called the d-spacing. 

The intensity of the d-space pattern is directly proportional to the number of electrons (atoms) in the imaginary planes. Every crystalline solid has a unique pattern of d-spacings (known as the powder pattern), which is a fingerprint for that solid. Solids with the same chemical composition but different phases can be identified by their pattern of d-spacings.