Self-diffusion along the [112] Shockley partial dislocation pair (pipe self-diffusion) was studied by using Nosé-Hoover molecular dynamics and the many-atom Ackland-Tichy-Vitek-Finnis model. The difference in formation energy between interstitials and vacancies at partial dislocations was found to be 1.3eV. Thermal disorder in the stacking-fault region made it very difficult to monitor the migration of single vacancies or interstitials for sufficiently long times at homologous temperatures of between 0.78 and 1. The diffusion which was produced by 1 vacancy and 1 interstitial, calculated for temperatures ranging from 1150 to 1400K, indicated migration energies of 0.75eV for the vacancy and 0eV for the interstitial. As the activation energy for interstitials was about 0.5eV larger than that for vacancies, pipe self-diffusion was more of vacancy-type than of interstitial-type. The components of the induced diffusion constants indicated the spread of diffusion into the entire stacking fault region.

Nosé-Hoover Molecular-Dynamics Study of Self-Pipe-Diffusion in Gold using Many-Atom Interactions. J.Von Boehm, R.M.Nieminen: Physical Review B, 1994, 50[9], 6450-2