A NEW MECHANISM FOR SURFACE-DIFFUSION - MOTION OF A SUBSTRATE-ADSORBATE COMPLEX

We propose a new mechanism for diffusion of surface adsorbates in whic h motion of the substrate atoms to which the adsorbates are attached r esults in the motion of the substrate-adsorbate complex. We show an ex perimental example-the motion of self-assembled monolayers of CH3O2C(C H2)(15)SH on gold which we have observed by time-lapse imaging using s canning tunneling microscopy. This mechanism is also used to explain p revious data for motion of Cu-O complexes on the Cu{110} surface.