Crystal-melt interfacial free energies and mobilities in fcc and bcc Fe

Molecular-dynamics simulations have been used to compute thermodynamic and kinetic properties of the solid-liquid interface for both the fcc and bcc phases of Fe. Pure Fe was modeled using two different interatomic potentials of the embedded atom type as well as an effective pair potential. Free solidification simulations were used to determine the kinetic coefficient mu for the different models of pure Fe. The anisotropy of mu with respect to growth direction in the bcc phase is similar to that observed in fcc systems, namely mu(100)>mu(110)similar tomu(111), and the kinetic coefficient of bcc is larger than mu for the fcc phase. The kinetic coefficient results are discussed in terms of a kinetic density-functional-theory-based model of crystal growth. In addition, results for solid-liquid interfacial free energies gamma computed via the capillary fluctuation method, are summarized.