X-ray crystallography

(redirected from X-ray scattering)
Also found in: Dictionary, Medical.
Related to X-ray scattering: XRD

X-ray crystallography,

the study of crystal structures through X-ray diffraction techniques. When an X-ray beam bombards a crystalline lattice in a given orientation, the beam is scattered in a definite manner characterized by the atomic structure of the lattice. This phenomenon, known as X-ray diffraction, occurs when the wavelength of X-rays and the interatomic distances in the lattice have the same order of magnitude. In 1912, the German scientist Max von Laue predicted that crystals exhibit diffraction qualities. Concurrently, W. Friedrich and P. Knipping created the first photographic diffraction patterns. A year later Lawrence Bragg successfully analyzed the crystalline structures of potassium chloride and sodium chloride using X-ray crystallography, and developed a rudimentary treatment for X-ray/crystal interaction (Bragg's Law). Bragg's research provided a method to determine a number of simple crystal structures for the next 50 years. In the 1960s, the capabilities of X-ray crystallography were greatly improved by the incorporation of computer technology. Modern X-ray crystallography provides the most powerful and accurate method for determining single-crystal structures. Structures containing 100–200 atoms now can be analyzed on the order of 1–2 days, whereas before the 1960s a 20-atom structure required 1–2 years for analysis. Through X-ray crystallography the chemical structure of thousands of organic, inorganic, organometallic, and biological compounds are determined every year.

Bibliography

See M. Buerger, X-Ray Crystallography (1980).

X-ray crystallography

The study of crystal structure by x-ray diffraction techniques. For the experimental aspects of x-ray diffraction See X-ray diffraction

Structurally, a crystal is a three-dimensional periodic arrangement in space of atoms, groups of atoms, or molecules. If the periodicity of this pattern extends throughout a given piece of material, one speaks of a single crystal. The exact structure of any given crystal is determined if the locations of all atoms making up the three-dimensional periodic pattern called the unit cell are known. The very close and periodic arrangement of the atoms in a crystal permits it to act as a diffraction grating for x-rays. See Crystallography

x-ray crystallography

[′eks ‚rā ‚krist·əl′äg·rə·fē]
(crystallography)
The study of crystal structure by x-ray diffraction techniques. Also known as roentgen diffractometry.
References in periodicals archive ?
He has initiated and worked on the X-ray scattering method for dimensional metrology during his last 14 years at NIST.
Furthermore, it can be combined, simultaneously and on the same samples, with the grazing incidence wide angle X-ray scattering or diffraction (GIWAXS) technique which is sensitive to the atomic arrangement and strain state.
To investigate the molecular packing and inner film morphology of the deposited films, X-ray scattering measurements in grazing incidence geometry were performed.
By contrast, inelastic X-ray scattering methods are useful in studying excitations of the sample, rather than the distribution of its atoms.
Faradaurate-940: Synthesis, Mass Spectrometry, Electron Microscopy, High- Energy X-ray Diffraction, and X-ray Scattering Study of Au~940 [+ or -] 20(SR)~160 [+ or -] 4 Nanocrystals.
In order to characterize the structure of the pure as well as the PCL containing [C.sub.12][E.sub.5] microemulsions we applied small angle X-ray scattering. The scattered intensity as a function of q for [C.sub.12][E.sub.5]/water/n-decane mixed with PCL is showed in Figure 3.
Equation (15) leads to the following expression for the smallangle X-ray scattering (SAXS) intensity, [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII].
Small-angle X-ray scattering (SAXS) is a nondestructive technique in morphological investigation of nanostructures [3].
With this takeover, Bruker will be able to extend its product offering for small angle X-ray scattering (SAXS) by adding Hecusa[euro](tm) MICROcaliX line, the buyer said in a statement.
Furthermore, scattering methods such as small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) are well suited to study these particles in dispersion.
It is the first time that metal nanoparticles have been used as agents to enhance X-ray scattering signals to image tumour-like masses.
Punegov, Theory of x-ray scattering on lateral structures, Syktyvkar, SyktGU, 2007.