Dresden 2014 – scientific programme
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MI: Fachverband Mikrosonden
MI 11: Crystallography in Materials Science (KR jointly with DF, MI)
MI 11.6: Talk
Thursday, April 3, 2014, 16:45–17:00, CHE 184
White beam synchrotron x-ray topography of sapphire single crystals — •Atefeh Jafari1,2, Angelica Cecilia3, Jürgen Härtwig4, Andreas Danilewsky5, Dimitrios Bessas4, Viktor Asadchikov6, Boris Roschin6, Denis Zolotov6, Alexander Deryabin6, Ilya Sergeev7, Svetoslav Stankov3, Tilo Baumbach3, Pavel Alexeev1,7, Hans-Christian Wille7, and Raphaël Hermann1,2 — 1Jülich Centre for Neutron Science JCNS and Peter Grünberg Institute PGI, JARA-FIT, Forschungszentrum Jülich, Germany — 2Faculté des Sciences, Université de Liège, Liège, Belgium — 3Institute for Photon Science and Synchrotron Radiation, KIT, Germany — 4European Synchrotron Radiation Facility, Grenoble, France — 5Crystallographic institute, University of Freiburg,Germany — 6Shubnikov Institute of Crystallography, RAS, Moscow, Russia — 7Deutsches Elektronen-Synchrotron, Hamburg, Germany
Sapphire single crystals grown by different techniques have been assessed with white beam and meV-resolution synchrotron x-ray topography at ANKA, KIT and PETRA III, DESY, and ESRF, respectively. Excellent crystal quality is required for the use in backscattering x-ray monochromators for nuclear resonance scattering with resonance energies above 30 keV. X-ray topography reveals defects and dislocations and hints at their origin. Crystals grown by the Kyropoulos method show the lowest dislocation density. Support of the Helmholtz-Russia joint research group HRJRG-402, ANKA, PETRA III and ESRF is acknowledged.