An embedded-atom potential for Fe was constructed by fitting both experimental and first-principles results. The potential reproduces with satisfactory accuracy the lattice properties, surface energies and point-defect energies for both body-centered cubic and the high temperature face-centered cubic phases of the metal. The potential was used in tandem with molecular-dynamics simulations to calculate the thermal expansion of both BCC-Fe and FCC-Fe, the phonon dispersion curves, mean-square displacements and surface relaxations of the element. In addition, self-diffusion of single adatoms on the BCC-Fe(100) surface at several temperatures was studied. The migration energies and pre-exponential factors for 3 main diffusion mechanisms were determined and compared with available experimental data. It was found that the diagonal exchange diffusion process was energetically favored over the direct hopping mechanism and that its migration energy was close to the experimental value. Furthermore, the diffusion coefficient associated with the diagonal exchange diffusion process was about an order of magnitude higher than those of the hopping and the non-diagonal exchange mechanisms.

Embedded-Atom Potential for Fe and Its Application to Self-Diffusion on Fe(100). H.Chamati, N.I.Papanicolaou, Y.Mishin, D.A.Papaconstantopoulos: Surface Science, 2006, 600[9], 1793-803