Surface relaxation and stress of fcc metals: Cu, Ag, Au, Ni, Pd, Pt, Al and Pb

Abstract

The multilayer relaxation at (100), (110), (111), (210), (211), (310), (311) and (331) surfaces of the fcc metals Cu, Ag, Au, Ni, Pd, Pt, Al and Pb are calculated using the modified embedded atom method. The 'anomalous' outward relaxation at Al (100), (111), Pt (111), and Cu (111) surfaces is described correctly. The relief of surface stress and tension on the relaxation is studied on (111), (100) and (110) surfaces. In general, the surface stress in the direction of the surface normal determines the relaxation direction except for the Al (110) surface. When the surface stress is negative, the surface relaxation is inward; otherwise, the relaxation is outward. An interesting result is that the surface tension does not always decrease after relaxation. The outward relaxation will induce the increase in surface tension while the inward relaxation induces the decrease in surface tension.