A study of the diffusion of Pb on the Au(111) surface by STM and EAM-MD simulations

Surface reconstructions often result in novel growth morphologies, and are therefore of potential technological interest. The Au(lll) surface will rec onstruct into the 22 x root 3 "herringbone" structure. Low coverages (up to 0.3 monolayers) have been studied with scanning tunneling microscopy (STM) at room temperature, to determine the impact of the reconstruction on diff usion and thin film growth. The same system has been studied using embedded -atom model molecular dynamics (EAM-MD). These simulations, in addition to providing morphological information, permit qualitative comparison of diffu sion phenomena. Experimental results indicate that initial sites for Pb ads orption are located at the herringbone kinks. For higher coverages, Pb pref ers hcp and fee stacking regions, avoiding the herringbone ridges. The reco nstruction is removed for some coverage between 0.05 and 0.2 monolayers. ST M and EAM results will be compared.