ISSN:
1600-5767
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Geosciences
,
Physics
Notes:
Superscrew dislocations are visible in back-reflection synchrotron white-beam X-ray topographs of basal-cut SiC wafers in striking contrast as black rings surrounding white circles, even though such topographs suffer from extensive harmonic contamination. The contributions to the synchrotron white-beam topograph of each member of its series of harmonic reflections, {\bf g}=(0006n), where n=3 to 16, were calculated. Through intensity considerations and comparison with a {\bf g}=00018 topograph taken with Cu Kα1 radiation, the {\bf g}=00024 harmonic was determined to be the most important contributor. The contrast of features lying deep beneath the crystal's surface was attributed to higher harmonics with larger penetration depths.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0021889898004683
