The mechanism of dislocation dipole annihilation was investigated in C and Si using atomistic calculations with the aim of studying their annihilation by-products. It was shown, in C as well as in Si, that dipole annihilation yields debris that can be depicted as a cluster of vacancies, or alternately by two internal free surfaces. These defects have no strain field and can hardly be seen using usual TEM techniques. This suggests that the brown colouration of diamond could be due to microstructures resulting from deformation mechanisms associated with dipole formation and their annihilation rather than to a climb mechanism and vacancy aggregation. In silicon where a number of dipoles were evidenced by TEM when dislocation trails were found, such debris could be the missing link responsible for the observation of strong chemical reactivity and electrical activity in the wake of moving dislocations.

Dislocation Dipole Annihilation in Diamond and Silicon. J.Rabier, L.Pizzagalli: Journal of Physics - Conference Series, 2011, 281[1], 012025