Dynamics of surface migration in the weak corrugation regime

We report a systematic study for metal-on-metal surface migration in the weak corrugation regime, i.e., with migration barriers falling below approximately 100 meV. The migration characteristics are elucidated by variable-temperature scanning tunneling microscopy observations in the 50-200 K temperature range, which are analyzed by means of nucleation theory. The results demonstrate that, upon entering the weak corrugation regime, the dynamics of the systems are characterized by increasingly reduced effective preexponential factors, while Arrhenius behavior prevails.