Diffusion of oxygen in nickel: A variable charge molecular dynamics study

摘要

Variable charge molecular dynamics have been performed to study the diffusion mechanisms of oxygenatoms (O) in nickel (Ni) in the temperature range 950 K1600 K. It is observed that oxygen does notdiffuse via jumps of oxygen through interstitial sites but via a vacancy diffusion mechanism. The oxygendiffusivity can be well described by an Arrhenius law over the temperature range considered. The oxygendiffusion coefficient has been analysed and indicates a value of Ea D 1:99 eV for the activation energyand D0 D 39:2 cm2 s for the pre-exponential factor. Our numerical results were compared with acompilation of experimental and theoretical studies, and exhibit a good agreement with the previousapproaches.