Reconstruction at Ordered Au(110)-Aqueous Interfaces as Probed by Atomic-Resolution Scanning Tunneling Microscopy.

摘要

Atomic resolution scanning tunneling microscopy (STM) images of ordered Au(110) in aqueous 0.1 M HC104, reported as a function of electrode potential, provide an unusually detailed picture of surface reconstruction. Lowering the potential of a freshly annealed surface to -0.3 V vs SCE yield images consisting primarily of domains having (1 x 2) symmetry. While the (1 x 2) structure exhibits an atomic density commensurate with the usual missing row model, the images suggest that significant relaxation of both top- and second-layer atoms occurs. Three-atom wide ribbons, lying along the (110) direction, are seen to provide the basic building blocks of the reconstruction; these units also yield added row domains of (1 x n) symmetry, where n=3 or higher. The reconstruction is lifted, yielding the (1x1) Au(110) surface, rapidly (within ca 2s) upon altering the potential to O V vs SCE, yet reappears immediately upon returning to -0.3 V.