Borrmann effect
From Online Dictionary of Crystallography
Effet Borrmann (Fr). Borrmann Effekt (Ge). Effetto Borrmann (It). ボルマン効果 (Ja). Бормана эффект (Ru). Efecto Borrmann (Sp).
Definition
Due to anomalous absorption, type 1 wavefields propagate in a perfect or nearly perfect crystal with a less than normal absorption. For details and the physical interpretation, see anomalous absorption.
Super-Borrmann effect
It is the enhancement of the Borrmann effect in a three-beam case, e.g. when the [math]111 [/math] and [math]{\bar 1}11 [/math] reflections are simultaneously excited in a silicon or germanium crystal.
History
The Borrmann effect was first discovered in quartz [Borrmann, G. (1941). Physik Z., 42, 157-162. Über Extinktionsdiagramme der Röntgenstrahlen von Quarz] and then in calcite crystals [Borrmann, G. (1950). Z. Phys. 127, 297-323. Die Absorption von Röntgenstrahlen in Fall der Interferenz], and interpreted by Laue [Laue, M. von (1949). Acta Cryst. 2, 106-113. Die Absorption der Röntgenstrahlen in Kristallen im Interferenzfall] .
The super-Borrmann effect was first observed by Borrmann, G. and Hartwig, W. [(1965). Z. Krist. 121, 401-409. Die Absorption der Röntgenstrahlen im Dreistrahlfall der Interferenz].
See also
- Chapter 5.1 of International Tables for Crystallography, Volume B for X-rays
- Chapter 5.2 of International Tables for Crystallography, Volume B for electrons
- Chapter 5.3 of International Tables for Crystallography, Volume B for neutrons