Premium
Diffraction Contrast from Dauphiné Twin Boundaries in Quartz
Author(s) -
McLaren A. C.,
Phakey P. P.
Publication year - 1969
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19690310233
Subject(s) - diffraction , contrast (vision) , quartz , crystal twinning , electron diffraction , crystallography , optics , materials science , reflection (computer programming) , extinction (optical mineralogy) , electron microscope , physics , chemistry , computer science , composite material , programming language , microstructure
Electron diffraction contrast evidence is obtained for the presence of Dauphiné twins in amethyst quartz. A model for the Dauphiné twin boundary which does not involve broken SiO bonds is proposed and shown to be consistent with the contrast features observed with different operating reflection. X‐ray diffraction topography of macroscopic Dauphiné twin boundaries in natural quartz show identical contrast effects and support the electron microscope observations. – It is shown that a different type of fringe pattern, not previously described, can arise at boundaries if the extinction distances in the two parts of the twin differ significantly. Diffraction contrast from such fringe patterns is described and explained using Gevers‐Amelinckx intensity relations.