Abstract
Screw superdislocations with hollow cores (dislocated micropipes) in silicon carbide bulk crystals were investigated by synchrotron phase radiography. Mapping of their distribution over the area and depth of SiC crystals by using phase radiographic imaging showed that, in the regions of their high density, micropipes reacted with each other. As the result of the reactions either usual pores or micropipe bundles and double spirals appeared; the latter sometimes transformed into dislocation semiloops. The computer simulation of the evolution of random ensemble of dislocated micropipes during crystal growth was done within the Newton's mechanics approach; it was demonstrated that the experimentally observed configurations of micropipes were caused by the mutual attraction of dislocations having Burgers vectors of opposite signs.