Bloch-wave channeling and HOLZ effects in high-energy electron diffraction

Abstract

The circular arcs and high-order Laue zone (HOLZ) fine lines observed in both Kikuchi-line and convergent-beam electron diffraction (CBED) patterns have been shown to be consistent with the concept of Bloch-wave channeling of fast electrons along rows of atoms. This interpretation has the advantages that it provides a direct correlation between HOLZ lines and the crystal periodicity along the incident-beam direction, and forms a basis which could be incorporated into a more rigorous electron diffraction theory in the future for understanding the extreme Laue and Bragg cases of electron diffraction, as well as the intermediate reflection and transmission high-energy electron diffraction (RTHEED). Examples are given of all three types of CBED, RHEED and RTHEED patterns from Pt and GaAs single crystals, which show the common dynamical diffraction effects, circular arcs and HOLZ fine lines, resulting from Bloch-wave channeling.