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 (mu), defined as the constant of proportionality between interface velocity and undercooling, is calculated for the three high-symmetry orientations (0001), (10 (1) over bar0), and (11 (2) over bar 0). The magnitudes of the interface mobilities are found to lie in the range of 40-80 cm/s/K. The mobilities mu(10 (1) over bar0) and mu(11 (2) over bar0) are found to be of comparable magnitude and approximately 1.7 times larger than mu(0001). The calculated dependence of mu on interface normal is discussed within the framework of the kinetic density-functional theory (DFT) formulation of Mikheev and Chernov.