The formation thermodynamics and migration properties of self-interstitials in Al and Ni were investigated as a function of temperature using atomistic simulation techniques and embedded-atom-type interatomic potentials. Molecular dynamics and non-equilibrium free-energy techniques were employed to investigate anharmonic effects on the HO ⟨100⟩ dumb-bell formation properties. The equilibrium concentration of this defect was compared to those of vacancies and divacancies. The results were then analyzed in the framework of the interstitialcy model, according to which very high vibrational formation entropies should be expected for self-interstitials at high temperatures. The kinetics of self-interstitial migration was also investigated using different atomistic techniques, revealing the simultaneous activity of more than one distinct interstitial configuration as the temperature increased.

Theoretical Study of the Thermodynamic and Kinetic Properties of Self-Interstitials in Aluminum and Nickel. S.R.de Debiaggi, M.de Koning, A.M.Monti: Physical Review B, 2006, 73[10], 104103 (9pp)