Abstract
A model for dislocation climb is proposed, and its underlying basis is that dislocations can act as sources and sinks for point defects. By invoking this property, the pair of point defects required for climb can be produced simultaneously at the dislocation core even when only one type of point defect is absorbed at the core. In real materials where supersaturation of one type of point defect is present, an asymmetry exists in the climb behaviour of α and β dislocations. Also, the presence of phase separation and atomic ordering in mixed III-V materials imposes a drag on dislocation climb. The supporting arguments have been developed.