Screw super-dislocations with hollow cores (pipes) which arise during growth of semiconductor crystals such as silicon carbide and GaN were considered. Exact analytical expressions were first derived for the displacements, strains, and stresses associated with a pipe oriented perpendicular to the free planar surface of an elastically isotropic half-space. It was shown that the stress field of the dislocation present in the pipe was heavily affected when the exact boundary conditions at the free cylindrical surface of the pipe were taken into account. The influence was the strongest in the region around the pipe at distances of the order of the pipe radius from the surface of the pipe. In this region, the elastic strains could be as large as a few tenths of one percent. The results obtained could be useful in analyzing the interaction of pipes with one another and with other defects, as well as in simulating the behavior of pipes during crystal growth.

Elastic Fields of a Screw Superdislocation with a Hollow Core (Pipe) Perpendicular to the Free Crystal Surface. A.G.Sheĭnerman, M.Y.Gutkin: Physics of the Solid State, 2003, 45[9], 1694-700