First-principles calculations of vacancy–solute element interactions in body-centered cubic iron

We have studied the vacancy–solute atom interactions in body-centered cubic Fe by means of first-principles calculations to obtain a better understanding of them for the application of ferritic steels, which are very important structural materials for fission and fusion reactors. The interactions between a vacancy and carbon/nitrogen interstitial atoms are studied in detail to obtain the binding energies and stable structures of the complexes. Substitutional atoms of 3d transition metals, such as Sc, Ti, V, Cr, Mn, Co, Ni, Cu and Zn, and of other important elements Si, P, S and Mo, are also studied to obtain their binding energies with a vacancy. The origin of the binding energies is discussed from the viewpoints of electronic structures and the distortion of the crystalline lattice.