High-resolution study of (222, 113) three-beam diffraction in Ge

Abstract

The results of high-resolution analysis of the (222, >113) three-beam diffraction in Ge are presented. For monochromatization and angular collimation of the incident synchrotron beam a multi-crystal arrangement in a dispersive setup in both vertical and horizontal planes was used in an attempt to experimentally approach plane-wave incident conditions. Using this setup, for various azimuthal angles the polar angular curves which are very close to theoretical computer simulations for the plane monochromatic wave were measured. The effect of the strong two-beam 222 diffraction was observed for the first time with the maximum reflectivity close to 60% even though the total reflection of the incident beam into a forbidden reflection was not achieved owing to absorption. The structure factor of the 222 reflection in Ge was experimentally determined.

High-resolution study of (002, 113, 11−1) four-beam diffraction in Si

“…The second region is the most interesting, because here the effect of total reflection in the forbidden direction was predicted theoretically by Kohn (1988a) and observed experimentally by Kazimirov & Kohn (2010, 2011. To illustrate the effect analytically we simplify the problem and consider hard radiation when the Bragg angles are small.…”

“…The effect was recorded under the necessary conditions. In the second work of this series (Kazimirov & Kohn, 2011) the three-beam (222, 113) case of X-ray diffraction in Ge was studied in detail under the conditions of rather good collimation and monochromatization. In this work both the central part of the azimuthal scan and the tails were registered.…”

A study of X-ray multiple diffraction by means of section topography

“…Meanwhile, for the detailed study of peculiarities of angular dependence of the plane-wave reflection, particularly for the study of the effect of total reflection of the forbidden reflected beam (Kon, 1988a,b), it is necessary to use the almost ideal plane and monochromatic wave, that was achieved experimentally only recently (Kazimirov & Kohn, 2010, 2011Kohn & Kazimirov, 2012).…”