A short review was presented of recent synchrotron white-beam X-ray topographic studies of defects in 4H- and 6H-type material. The defects which were observed included closed-core and hollow-core screw dislocations (micro-pipes) in both materials, deformation-induced basal-plane dislocations in both materials and low-angle boundaries in 4H-type material alone. These studies included an analysis of the relationship, between the hollow-core diameter and the Burgers vector for micro-pipes, by using synchrotron white-beam X-ray topography and scanning electron microscopy. They also covered the use of a set of synchrotron white-beam X-ray topographic techniques, and associated simulations, for characterizing micro-pipes and closed-core screw dislocations. The nucleation mechanism of micro-pipes, as deduced using synchrotron white-beam X-ray topography together with other techniques, was also considered.

Characterization of SiC using Synchrotron White Beam X-ray Topography. M.Dudley, X.Huang: Materials Science Forum, 2000, 338-342, 431-6