First principles calculation of boron diffusion in fcc-Fe

The diffusion mechanism of boron in fcc-Fe was studied by first-principles calculations. The sites where B atoms tend to occupy and the diffusion behavior were calculated. Results indicated that the main mechanism of boron diffusion in fcc-Fe was the B–monovacancy complex mechanism instead of the interstitial mechanism. The diffusion coefficient D1 of the B–monovacancy complex mechanism was calculated without considering the backward jump of the B atoms. The calculated D1 = 1.26 × 10−4 × exp(–2.01eV/kBT) m2·s−1 is consistent with the reported results from experiments. [Display omitted] •The boron atoms tend to occupy the substitutional sites in fcc-Fe.•The main diffusion mechanism of boron in fcc-Fe is boron-monovacancy complex mechanism.•The divacancy only slightly influences diffusion.•The calculated diffusion coefficient agreed closely with the experimental results when ignoring the back-jump of boron atoms.