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Bragg's law. Physical law regarding scattering angles of radiation through a medium. In many areas of science, Bragg's law, Wulff –Bragg's condition, or Laue–Bragg interference are a special case of Laue diffraction, giving the angles for coherent scattering of waves from a large crystal lattice. It describes how the superposition of wave ...
In X-ray crystallography, wide-angle X-ray scattering (WAXS) or wide-angle X-ray diffraction (WAXD) is the analysis of Bragg peaks scattered to wide angles, which (by Bragg's law) are caused by sub-nanometer-sized structures. [1] It is an X-ray-diffraction [2] method and commonly used to determine a range of information about crystalline materials.
X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering, when there is no change in the energy of the waves. The resulting map of the directions of the X-rays far from the sample is called a diffraction pattern.
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallographer can produce a three-dimensional picture of ...
Characteristic X-ray spectroscopy. When an electron from the inner shell of an atom is excited by the energy of a photon, it moves to a higher energy level. When it returns to the low energy level, the energy it previously gained by excitation is emitted as a photon of one of the wavelengths uniquely characteristic of the element.
Dark-field X-ray microscopy. Dark-field X-ray microscopy (DFXM[1] or DFXRM[2]) is an imaging technique used for multiscale structural characterisation. It is capable of mapping deeply embedded structural elements with nm-resolution using synchrotron X-ray diffraction -based imaging. The technique works by using scattered X-rays to create a high ...
HAADF. High-angle annular dark-field imaging (HAADF) is a STEM technique which produces an annular dark field image formed by very high angle, incoherently scattered electrons (Rutherford scattered from the nucleus of the atoms) — as opposed to Bragg scattered electrons. This technique is highly sensitive to variations in the atomic number of ...
The International Centre for Diffraction Data (ICDD) maintains a database of powder diffraction patterns, the Powder Diffraction File (PDF), including the d-spacings (related to angle of diffraction) and relative intensities of observable diffraction peaks. Patterns may be experimentally determined, or computed based on crystal structure and ...