Role of the third element in accelerating Fe diffusivities in Cu from first principles

Iron diffusion in face-centered cubic (fcc) copper affected by a third element have been computed from first principles using density-functional theory (DFT). The five frequency model was employed to determine impurity diffusion coefficients through atomistic structure calculations. The self-diffusion coefficient of Cu and impurity diffusion coefficients in Cu agreed well with experimental measurements available. Specifically, an eight frequency model was built based on the five frequency model to investigate the changes in Fe diffusivities, both the diffusion pre-factor D0 and the activation energy after adding the third element were calculated. The results showed that 9 potential elements may accelerate significantly iron diffusion in copper.