Dislocation pinning by glissile interstitial loops in a nickel crystal: A molecular-dynamics study

Molecular-dynamics simulations show that, in an embedded-atom method nickel crystal, interstitial loops made of $〈110〉$ dumbbells may be absorbed by an edge dislocation in two different ways, either being attached to one of the Shockley partials by means of a dislocation junction or being transformed into a double superjog on the dislocation. In both cases, the absorption is assisted by a flip of the loop Burgers vector. The simulations also show that double superjogs lock the dislocation but are only weak obstacles. In all cases, the loops may be dragged by the dislocation and induce on the latter an additional friction which is evaluated from the simulations.