Relaxation at High-Index Surfaces Studied by Atomic-Resolution Scanning TunnelingMicroscopy: Au(311), (533) and (221) Electrochemical Interfaces

摘要

Atomic relaxation at the stepped surfaces Au(311), (533), and (221) in aqueoussolution is examined by atomic-resolution scanning tunneling microscopy (STM). The former two surfaces yield ordered (1 x 1) domains at electrode potentials corresponding to near-zero or positive electronic charges. Substantial surface relaxation is observed, however, at more negative potentials, featuring displacements of the step edge and neighboring atomic rows. The Au(221) surface exhibits a marked relaxation at positive as well as negative electronic charges. The so-far underutilized value of STM for exploring atomic structure at stepped surfaces is demonstrated by these findings.