Bloch wave treatment of electron channeling

Electron channeling patterns have been recorded at 100 kV and 1 MV from thick crystals of various substances using the electron microscope. The directions of high penetration near a zone axis appear as groups of diffuse spots which can be associated with simple antisymmetrical Bloch waves with very few plane wave components. Patterns around a [001] zone axis are considered in detail and compared with calculations based upon a simplified theory of multiple diffuse scattering, especially for patterns from silicon and uranium dioxide. Agreement between experimental and calculated patterns, using 54 beams, is good. (Auth.)