Direct observation of an ordered step surface reconstruction on Au(111) by scanning tunneling microscopy

Experiments with a scanning tunneling microscope (STM) are reported which include the first surface topographic images of Au(111), cleaned and annealed in ultrahigh vacuum. The STM system used for this work includes in situ sample manipulation for sample cleaning, annealing and characterization. Topographs with very large atomically flat (111) regions are obtained and no corrugation on the scale of about 0.1 Å is observed. Some single atomic steps are observed. Surprisingly, ordered arrays of single steps are observed over a large region. These represent a type of surface reconstruction whose repeat period agrees with values derived from previous LEED, TEM and ion scattering measurements. These results represent the first critical information about the surface topography of the Au(111) surface.