A molecular-dynamics study of the anisotropic surface-melting properties of Al(110)

Surface melting of Al(110) was studied by molecular dynamics simulations wi th a well tested glue potential. We found that the surface began to disorde r above 600 K via the formation of adatoms and vacancies. While bulk meltin g was observed at 945 K (experimental melting point is 933.5 K), the top fo ur atomic layers were found to become liquid-like just before the bulk melt s. Both the diffusion constants and the structure factors confirmed that su rface melting of Al(110) was anisotropic, with random atom motion faster in the [110] direction than in the [100] direction. On the other hand, in agr eement with recent experimental observations [M. Polcik et al., Phys. Rev. Lett. 78 (1997) 491], our calculations showed the presence of a residual or der preferentially along the [1 (1) over bar 0] direction via the presence of intact [110] atom chain segments, even above 900 K. (C) 1999 Elsevier Sc ience B.V. All rights reserved.