A first-principles study of the diffusion of atomic oxygen in nickel

Highlights: •The diffusion process of atomic oxygen in nickel is modeled. •Density functional theory is used to calculate the activation energy of diffusion. •Oxygen diffusivities in nickel are estimated by a vacancy-mediated diffusion model. •The calculated diffusivities are compared with those observed experimentally. -- Abstract: In this study, the coefficients of diffusion of oxygen in nickel-based alloys are determined by atomistically modeling the oxygen diffusion process using a vacancy-mediated diffusion model. Density functional theory is used to calculate the energy of the system. The activation barrier energy for the diffusion of atomic oxygen in nickel is quantified by determining the most favorable path, i.e., the minimum-energy path, for diffusion. Phonon analysis is performed using the direct force-constant method. The calculated pre-exponential factor for the lattice diffusion of oxygen in nickel is 5.45 × 10−7 m2/s and the activation energy is 158.65 kJ/mol