%0 Journal Article
%A Jafari, A.
%A Sergueev, I.
%A Bessas, D.
%A Roschin, B. S.
%A Asadchikov, V. E.
%A Alexeev, P.
%A Härtwig, J.
%A Chumakov, A. I.
%A Wille, H.-C.
%A Hermann, Raphael
%A Klobes, Benedikt
%T Rocking curve imaging of high quality sapphire crystals in backscattering geometry
%J Journal of applied physics
%V 121
%N 4
%@ 1089-7550
%C Melville, NY
%I American Inst. of Physics
%M FZJ-2017-01517
%P 044901 
%D 2017
%X We report on the characterization of high quality sapphire single crystals suitable for high-resolution X-ray optics at high energy. Investigations using rocking curve imaging reveal the crystals to be of uniformly good quality at the level of ∼10−4 in lattice parameter variations, δd/d. However, investigations using backscattering rocking curve imaging with a lattice spacing resolution of δd/d∼5×10−8 show very diverse quality maps for all crystals. Our results highlight nearly ideal areas with an edge length of 0.2–0.5 mm in most crystals, but a comparison of the back reflection peak positions shows that even neighboring ideal areas exhibit a relative difference in the lattice parameters on the order of δd/d=10–20×10−8; this is several times larger than the rocking curve width. Stress-strain analysis suggests that an extremely stringent limit on the strain at a level of ∼100 kPa in the growth process is required in order to produce crystals with large areas of the quality required for X-ray optics at high energy.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000393480100032
%R 10.1063/1.4974106
%U https://juser.fz-juelich.de/record/827388