The inhomogeneity of a free-fall grown crystal of Te-doped material was studied by using quantitative plane-wave X-ray topography. The crystal was free of striations, whereas the Te distribution over its cross-section was noticeably non-uniform. A region formed by the advance of a facet present at the growth front was revealed. This region was enriched in Te and contained several striations; at one of which a twin originated. Conditions were suggested for growing high-quality crystals in free-fall via the Bridgman method. These were a reasonably small clearance between the growing crystal and the ampoule wall, and zero growth-front faceting.

Te Distribution in Space-Grown GaSb. A.E.Voloshin, T.Nishinaga, P.Ge, C.Huo: Journal of Crystal Growth, 2002, 234[1], 12-24