Roughening of the Pb (110) surface: combined Monte Carlo and molecular-dynamics study

Abstract

The roughening transition on the Pb (110) surface has been studied using a combination of lattice-gas Monte Carlo and molecular-dynamics methods in conjunction with a many-body glue potential. Lattice-gas Monte Carlo simulations yield a roughening transition temperature of approximately T R LGMC ≈ 1100 K. Molecular-dynamics simulations, which account for surface relaxation and lattice vibrations, detect the roughening transition at T R MD ≈ 545 K, above the high-resolution low-energy diffraction measurements of T R EXP ≈ 415 K. The anisotropic body-centered solid-on-solid model is used in the interpretation of these results. The time scale of local roughening at 545 K is about 0.6 ns. The time evolution of the Pb (110) surface from an initially smooth to a rough configuration is illustrated by the use of modem visualization techniques. Means for improving the theoretical results are discussed.