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Electron

  Electron Diffraction and the Reciprocal Lattice     2 of 8
 

The Ewald sphere for high energy electrons has a large radius (because l is so small) and therefore it samples a virtually plane section of the reciprocal lattice, often the zero order Laue zone. Because of relrod streaking there are usually many spots in the recorded diffraction pattern. Electron diffraction patterns can be equated with reciprocal lattice patterns.

Indexing

It is often possible to index an electron diffraction pattern by noting its symmetry. A reciprocal lattice has the same symmetry as its real lattice.

Have a go imageThis simulation shows a 2-D representation of a large radius Ewald sphere intersecting a reciprocal lattice. Try to identify the zero order and first order diffraction spots.

If insufficient obvious symmetry is present it may be necessary to use the ratio technique described in the next section.


Questions imageWhy are streaking effects more important for electron diffraction than for x-ray diffraction?

 

 
 

 Introduction  | Geometry | Intensity | X-ray Diffraction | Electron Diffraction 

 
 

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