Molecular dynamics calculations of the crystal-melt interfacial mobility for hexagonal close-packed Mg

The kinetics of crystallization from the melt is investigated for hcp Mg employing molecular dynamics simulations based on a recently developed embedded-atom-method interatomic potential. The interface mobility (μ), defined as the constant of proportionality between interface velocity and undercooling, is calculated for the three high-symmetry orientations (0001), (10 1̄ 0), and (11 2̄ 0). The magnitudes of the interface mobilities are found to lie in the range of 40-80 cm s K. The mobilities μ10 1̄ 0 and μ11 2̄ 0 are found to be of comparable magnitude and approximately 1.7 times larger than μ0001. The calculated dependence of μ on interface normal is discussed within the framework of the kinetic density-functional theory (DFT) formulation of Mikheev and Chernov.