Greninger chart
Encyclopedia
In crystallography
, a Greninger chart is a chart that allows angular relations between zones and planes in a crystal
to be directly read from an x-ray diffraction photograph.
The Greninger chart is a simple trigonometric tool to determine g and d for a fixed sample-to-film distance. (If one uses a 2-d detector the problem of determining g and d could be solved mathematically using the equations which generate the Greninger chart) A new chart must be generated for different sample to detector distances. (2s is 2q for the diffraction peak and tan m is x/y for the Cartesian coordinates of the diffraction peak.) The Greninger chart gives directly the two angles needed to plot poles on the Wulff net. It is critical to keep track of the relative arrangement of the sample to the film, if photographic film is used then this is achieved by cutting the corner of the film. For Polaroid
film one must make a note of the arrangement of the face of the film in the camera.
Crystallography
Crystallography is the experimental science of the arrangement of atoms in solids. The word "crystallography" derives from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and grapho = write.Before the development of...
, a Greninger chart is a chart that allows angular relations between zones and planes in a crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
to be directly read from an x-ray diffraction photograph.
The Greninger chart is a simple trigonometric tool to determine g and d for a fixed sample-to-film distance. (If one uses a 2-d detector the problem of determining g and d could be solved mathematically using the equations which generate the Greninger chart) A new chart must be generated for different sample to detector distances. (2s is 2q for the diffraction peak and tan m is x/y for the Cartesian coordinates of the diffraction peak.) The Greninger chart gives directly the two angles needed to plot poles on the Wulff net. It is critical to keep track of the relative arrangement of the sample to the film, if photographic film is used then this is achieved by cutting the corner of the film. For Polaroid
Instant film
Instant film is a type of photographic film first introduced by Polaroid that is designed to be used in an instant camera...
film one must make a note of the arrangement of the face of the film in the camera.
External links
- http://www.answers.com/topic/greninger-chart
- http://www.smartdefine.org/Greninger_chart
- http://www.eng.uc.edu/~gbeaucag/Classes/XRD/Labs/Lab3Laue.html
- http://www-xray.fzu.cz/xraygroup/www/grchart.html