Rapid adatom island decay on Cu(111): a kinetic Monte Carlo simulation study

摘要

Kinetic Monte Carlo (KMC) simulations are used to investigate the recent scanning tunneling microscopy (STM) measurements of fast decaying adatom islands on Cu(111). The KMC model is a full diffusion bond-counting model including nearest neighbor as well as second-nearest neighbor interactions. For encounters between steps in adjacent atomic layers of an island it is demonstrated that a moderately reduced activation energy for interlayer adatom transport is enough to obtain correspondence between simulations and experiments, provided that the one-dimensional Ehrlich-Schwoebel barrier for corner transitions is reduced to zero. The results presented in this report are interesting because they demonstrate that step-edge crossing by simple adatom hopping is sufficient to explain the rapid island-decay mechanism.