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X-ray diffraction




The diffraction of X-rays by the atoms or ions of a crystal, according to a characteristic pattern that enables information to be obtained on the structure of the crystal. X-ray diffraction was discovered by Max von Laue (1912) and developed for crystal analysis (X-ray crystallography) by William Henry and William Lawrence Bragg (1912–13).

The atomic nuclei in a crystal lattice act as diffraction gratings; the planes of atoms have spacings of a few angstrom units, which are comparable with the wavelengths of X-rays. Strong scattering of the rays by the crystal therefore occurs in certain directions, according to Bragg's law. Various techniques are available for applying X-ray diffraction to the study of single crystals, powders, fibers, etc., and by computation it is possible to work out three-dimensional electron density maps of the solid lattice from the recorded X-ray patterns.


Related categories

   • ATOMIC AND NUCLEAR PHYSICS
   • OPTICS AND OPTICAL PHENOMENA