Climb of edge dislocations in plastically deformed GaP

Abstract
The climb of edge dislocations in plastically deformed GaP doped with sulphur is examined in detail using transmission electron microscopy (TEM). An attempt is made to describe the climb mechanism quantitatively. It is assumed that the phosphorus vacancy Vp is the dominant point defect and climb is shown to be largely due to the concentration gradient of Vp. The climb velocity of isolated Lomer edge dislocations has been measured experimentally by TEM. From this value the diffusion coefficient of Vp is estimated to be (1·0-17) × 10−20 m2s−1 for T = 878 K.