The effect of point defects on diffusion pathway within α-Fe

Abstract

The diffusion mechanism of point defects within α-Fe with a single vacancy is investigated using the density functional theory. Calculation reveals that H has a slight effect towards Fe diffusion to a vacancy. He has a strong binding with a vacancy; therefore, Fe diffusion is unlikely to happen. The diffusion of C and N from a vacancy has a high barrier. However, Fe diffusion to a vacancy decreases if the C and N diffuse from a vacancy. Thus, the effect of interstitial atoms within α-Fe with a single vacancy towards diffusion and a possible diffusion pathway is discussed.

Nitrogen diffusion in vacancy-rich ferrite and austenite, from first principles to applications

“…Many sources [8,9] report that the energy barrier for nitrogen diffusion obtained by DFT calculations using ferromagnetic BCC iron has strong agreement to the low-temperature energy barrier obtained from experimental data for α Fe [10]. The situation is more challenging for γ Fe since it is both unstable at low temperatures (at high Fe purity) and paramagnetic, which are not readily incorporated features in DFT modelling.…”