Theoretical study of thermodynamic and migration properties of self-interstitials in aluminum and nickel

S. RAMOS DE DEBIAGGI; M. DE KONING; A. MONTI

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

American Physical Society Journals

Lugar: New York; Año: 2006 vol. 73 p. 1 - 9

0163-1829

The formation thermodynamics and migration properties of self-interstitials in aluminum and nickel are investigated as a function of temperature using atomistic simulation techniques and embedded-atom type interatomic potentials. Molecular dynamics and non-equilibrium free-energy techniques are employed to investigate anharmonic effects on the Ho -<100> dumbbell formation properties. The equilibrium concentration of this defect is compared to that of vacancies and divacancies. The results are 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 is also investigated using different atomistic techniques, revealing the simultaneous activity of more than one distinct interstitial configurations as the temperature increases.