Borrmann effect

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Effet Borrmann (Fr). Borrmann Effekt (Ge). Effetto Borrmann (It). Efecto Borrmann (Sp).

Contents

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 111 and {\bar 1}11 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