Formation Of Dislocation Pileup by Frank–Read Source

Abstract

Dislocation pileups play an important role in the formation and propagation of strain in single crystals and polycrystals. They are the main source of cracking. Dislocation pileups are often referred to as the cause of serrated plastic strain pattern and degradation of the external quantum efficiency of UV LEDs. A dynamic physical model describing the formation of dislocation pileup by Frank–Read source has been presented that allows characterizing not only the structure but also time parameters of pileups. We provide data on the dislocation pile−ups e.g. dislocation configuration in a pileup, number of dislocations in a pile−up as a function of external stress, formation time of new dislocation loops and time to source blocking by the opposite strain generated by pileup dislocations. We compare our experimental results for pileups formed by Frank–Read source with results for pileups of straight edge dislocations. A large calculation effort is required to take into account the interaction of pileup dislocations. To accelerate our calculations we conducted them in parallel runs using a Т−Edge−10 38−nuclei cluster.