ISSN:
1600-5724
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
A detailed analysis of a three-beam diffraction dispersion surface is performed to study the forbidden wavefields of thick-crystal Bragg reflections. From the asymptotic transition between two- and three-beam diffraction, it is found that the excitation state of each wavefield can be accurately determined with the two-beam criterion. Consequently, Bragg-case three-beam diffraction from thick crystals is either a four-mode diffraction process for the Bragg–Laue geometry or a two-mode process for the Bragg–Bragg geometry, and the amplitudes of the excited wavefields can be completely determined by the entrance boundary conditions. Based on this picture, the intrinsic mechanisms underlying three-beam Bragg reflections are clearly illustrated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0108767300013180
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