Editing Standing wave (section)

=== X-rays ===
Interference between [[X-ray]] beams can form an [[X-ray standing wave]] (XSW) field.<ref name="batterman_1964">{{cite journal | doi = 10.1103/RevModPhys.36.681 | bibcode=1964RvMP...36..681B | volume=36 | issue=3 | title=Dynamical Diffraction of X Rays by Perfect Crystals | year=1964 | journal=Reviews of Modern Physics | pages=681–717 | last1 = Batterman | first1 = Boris W. | last2 = Cole | first2 = Henderson}}</ref> Because of the short wavelength of X-rays (less than 1 nanometer), this phenomenon can be exploited for measuring atomic-scale events at material [[Surface science|surfaces]]. The XSW is generated in the region where an X-ray beam interferes with a [[Bragg diffraction|diffracted]] beam from a nearly perfect [[single crystal]] surface or a reflection from an [[X-ray reflectivity|X-ray mirror]]. By tuning the crystal geometry or X-ray wavelength, the XSW can be translated in space, causing a shift in the [[X-ray fluorescence]] or [[photoelectron]] yield from the atoms near the surface. This shift can be analyzed to pinpoint the location of a particular atomic species relative to the underlying [[crystal structure]] or mirror surface. The XSW method has been used to clarify the atomic-scale details of [[Semiconductor doping|dopants]] in semiconductors,<ref>{{cite journal | doi = 10.1103/PhysRevLett.22.703 | bibcode=1969PhRvL..22..703B | volume=22 | issue=14 | title=Detection of Foreign Atom Sites by Their X-Ray Fluorescence Scattering | year=1969 | journal=Physical Review Letters | pages=703–705 | last1 = Batterman | first1 = Boris W.}}</ref> atomic and molecular [[adsorption]] on surfaces,<ref>{{cite journal | doi = 10.1103/PhysRevLett.49.560 | bibcode=1982PhRvL..49..560G | volume=49 | issue=8 | title=Solution to the Surface Registration Problem Using X-Ray Standing Waves | year=1982 | journal=Physical Review Letters | pages=560–563 | last1 = Golovchenko | first1 = J. A. | last2 = Patel | first2 = J. R. | last3 = Kaplan | first3 = D. R. | last4 = Cowan | first4 = P. L. |author5-link=Michael Bedzyk | last5 = Bedzyk | first5 = M. J.| url=https://dash.harvard.edu/bitstream/handle/1/29407052/SolutionToTheSurfaceRegistrationProblem.pdf?sequence=1 }}</ref> and chemical transformations involved in [[Heterogeneous catalysis|catalysis]].<ref>{{cite journal | last1 = Feng | first1 = Z. | last2 = Kim | first2 = C.-Y. | last3 = Elam | first3 = J.W. | last4 = Ma | first4 = Q. | last5 = Zhang | first5 = Z. | last6 = Bedzyk | first6 = M.J. | year = 2009 | title = Direct Atomic-Scale Observation of Redox-Induced Cation Dynamics in an Oxide-Supported Monolayer Catalyst: WO<sub>''x''</sub>/α-Fe<sub>2</sub>O<sub>3</sub>(0001) | journal = J. Am. Chem. Soc. | volume = 131 | issue = 51| pages = 18200–18201 | doi = 10.1021/ja906816y | pmid = 20028144 }}</ref>