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Difference between revisions of "Borrmann effect"

From Online Dictionary of Crystallography

 
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== Super-Borrmann effect ==
 
== Super-Borrmann effect ==
  
It is the enhancement of the Borrmann effect in a three-beam case, ''e.g.'' when the 111 and -111 reflections are simultaneously excited in a silicon or germanium crystal.  
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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 ==
 
== History ==
  

Revision as of 17:11, 26 January 2006

Borrmann effect

Other languages

Effet Borrmann (Fr). Borrmann Effekt (Ge). 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, 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