Home Zur Absorption der Ewaldwellen; Messungen bei simultaner Reflexion an (111) und ([unk]11) des Germaniums
Article
Licensed
Unlicensed Requires Authentication

Zur Absorption der Ewaldwellen; Messungen bei simultaner Reflexion an (111) und ([unk]11) des Germaniums

Published/Copyright: July 28, 2010
Become an author with De Gruyter Brill

Abstract

The paper deals with anomalous transmission (Borrmann effect). The least-absorbable Ewald wave, arising in a perfect crystal under the condition of Braggs law, exceeds the stronger absorbed waves more and more with the growing thickness of the crystal. As a matter of fact, the absorption coefficient μ(t) at the depth t decreases with increasing t. μ(t) tends towards the minimum absorption coefficient μmin but cannot reach it at a finite thickness. This was proved in the case of simultaneous reflection of x-rays by the (111) and ([unk]11) lattice planes of a Ge crystal, when μmin was expected to be extremely low (μmin = 0.053 μ with λ = 1.54 Å, and only 0.022 μ with λ = 0.71 Å; μ normal absorption coefficient). According to theory the three waves of this least-absorbed Ewald wave have the intensity ratio of 2:1:1. The observed three reflections had the strength ratio of 2.3:1:1 (λ = 1,54 Å) and 2.15:1:1 (λ = 0.71 Å).

Published Online: 2010-07-28
Published in Print: 1969-05
Downloaded on 20.9.2025 from https://www.degruyterbrill.com/document/doi/10.1524/zkri.1969.129.1-4.1/html
Scroll to top button