Dislocations in high-quality heat-exchanger method sapphire were analyzed by using the white-beam large-area transmission synchrotron X-ray topographic technique. By analyzing dislocations for various Laue spots (various diffraction vectors) on one film, 3 types of dislocation (screw, edge, mixed) were identified; but most were of mixed type and their Burgers vectors belonged to <2¯1•0> and <10•0>.

Dislocation Analysis for Heat-Exchanger Method Grown Sapphire with White Beam Synchrotron X-ray Topography. W.M.Chen, P.J.McNally, Y.V.Shvydko, T.Tuomi, A.N.Danilewsky, M.Lerche: Journal of Crystal Growth, 2003, 252[1-3], 113-9