Large angle convergent beam electron diffraction

Electron Diffraction (CBED) and Large-Angle Convergent-Beam Electron Diffraction (LACBED) allow the identification of the crystal system, the Bravais lattice and the point and space groups. These crystallographic features are obtained at microscopic and nanoscopic scales from the observation of symmetry elements present on electron diffraction patterns. 

Large Angle Convergent Beam Electron Diffraction (LACBED)... 

J. P. Momiroh, Large-Angle Convergent Beam Electron Diffraction, Enghsh Version , Society of French Microscopists, Paris, 2002. 

Fig. 5.10 (a) Bright-field pattern, (b) dark-field pattern, (c) large angle convergent-beam electron diffraction pattern. The inset shows how to select a beam using a selective aperture (indicated by... 

Electron Diffraction (SAED), Microdiffraction, Convergent-Beam Eleetron Diffraetion (CBED), Large-Angle Convergent-Beam Eleetron Diffraetion (LACBED) and electron precession. They produee spot, ring, disk or line patterns at microseopie or nanoseopie seales in eorrelation with the image of the diffracted area. An overview of the main applieations is given. 

For a long time, Selected-Area Electron Diffraction (SAED) performed with a parallel incident beam and a selected-area aperture was the only experimental method available. During the three last decades, new diffraction techniques based on a convergent electron incident beam (CBED Convergent-Beam Electron Diffraction, LACBED Large-Angle... 

Convergent beam electron diffraction (CBED) strictly refers to diffraction using an electron probe in a TEM with very large convergence angle. When this convergence angle becomes small the conditions are similar to the spot pattern obtained with parallel illumination in the conventional Selected Area Diffraction Patterns (SADP) as is shown in Fig. 1. 

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