Anharmonic effects on Ag(111): a molecular dynamics study

We have explored the structure and dynamics of Ag(111) in the temperature r ange 300-1100 K, using molecular dynamics simulations and interaction poten tials from the embedded atom method. Calculated shifts in the surface phono n frequencies, the broadening of their line-widths, and the variations in t he mean square vibrational amplitudes of surface atoms, with temperature, i ndicate that anharmonic effects are small up to 900 K, beyond which there i s an enhancement. Thermal expansion is found to be about the same as in the bulk, and the surface does not disorder until 1100 K and does nor premelt. (C) 2000 Published by Elsevier Science B.V. All rights reserved.