3.5: Borrmann Effect
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 \( 111\) and \(\overline{111}\) reflections are simultaneously excited in a silicon or germanium crystal.
History
The Borrmann effect was first discovered in quartz (Borrmann G., 1941, Über Extinktionsdiagramme der Röntgenstrahlen von Quarz . Physik Z. , 42 , 157-162) and then in calcite crystals (Borrmann G., 1950, Die Absorption von Röntgenstrahlen in Fall der Interferenz. Z. Phys. , 127 , 297-323), and interpreted by Laue (Laue, M. von, 1949, Die Absorption der Röntgenstrahlen in Kristallen im Interferenzfall. Acta Crystallogr . 2 , 106-113).
The super-Borrmann effect was first observed by Borrmann G. and Hartwig W. (1965), Die Absorption der Röntgenstrahlen im Dreistrahlfall der Interferenz . Z. Krist. , 121 , 401-409.
See also
- Section 5.1 of International Tables of Crystallography, Volume B for X-rays
- Section 5.2 of International Tables of Crystallography, Volume B for electrons
- Section 5.3 of International Tables of Crystallography, Volume B for neutrons