Two types (scratched or deformed under uniaxial compression) of dislocated float-zone crystal were investigated by using cathodoluminescence techniques. In the former samples, dislocation-related luminescence (D-lines) was observed near to the scratches after H-treatment, but was not detected immediately after scratching. This indicated that mechanical scratching at room temperature introduced both radiative and non-radiative centers, and that H plasma passivated only non-radiative centers. In the latter case, D1 and D2 were detected at the intersection of various slip planes, while D3 and D4 were observed along slip lines. This showed that D1 and D2 originated from the reaction products of dislocations. It was noted that Lomer-Cottrell dislocations could be more effective centers for D1 and D2 luminescence than were jogs. The D3 and D4 lines were attributed to the normal portions of dislocations.

T.Sekiguchi, K.Sumino: Materials Science Forum, 1995, 196-201, 1201-6