Article contents
Synchrotron X-Ray Powder Diffraction
Published online by Cambridge University Press: 29 November 2013
Extract
X-ray powder diffraction is one of the most widely used techniques by scientists engaged in the synthesis, analysis, and characterization of solids. It is estimated that there are now about 25,000 users throughout the world, of which about one third are in the United States. Any single-phase polycrystalline material gives an x-ray pattern which can be regarded as a unique “fingerprint,” and modern automated search-and-match techniques used in conjunction with the Powder Diffraction File (maintained by the International Center for Diffraction Data, Swarthmore, PA) allow routine analysis of samples in minutes. From an x-ray pattern of good quality it is possible to determine unit cell parameters with high accuracy and impurity concentrations of 1-5%, so that powder techniques are extremely valuable in phase equilibrium studies and residual stress measurements, for example. In addition, a detailed analysis of line shapes gives information about physical properties such as the size and shape of the individual crystallites, microscopic strain, and stacking disorder.
In the early days of crystallography many simple (and some not-so-simple) structures were solved from x-ray powder diffraction patterns, but the obvious limitations to the number of individual reflection intensities which can be estimated and the increasing sophistication of single-crystal techniques resulted in a decline in the importance of this application in the 1950s and 1960s.
- Type
- Technical Features
- Information
- Copyright
- Copyright © Materials Research Society 1987
References
- 1
- Cited by