High‐Resolution Microscopy of Dissociated Screw Dislocations in GaAs

The structure of dissociated screw dislocations in GaAs is analyzed by high‐resolution electron microscopy and image simulation. The stacking fault is invariably found to be intrinsic with a stacking‐fault energy of (45 ± 6) mJ/m2. The comparison between experimental and simulated images suggests that partial dislocation motion occurs during observation and the interaction of the dislocation core with point defects severely limits the determination of the dislocation core structure in terms of “glide” or “shuffle” models. Copyright © 1989 WILEY‐VCH Verlag GmbH & Co. KGaA