Preparation and characterization of ultra-flat single crystal surfaces of Pd(1 1 1) and Au(1 1 1) by an in situ interference optical microscopy

It is shown that the Pd(1 1 1) and Au(1 1 1) surfaces with wide atomically flat terraces having widths in a range of 2–10 μm can be prepared by annealing in an argon stream. These surfaces were investigated by a laser confocal microscope combined with a differential interference contrast microscope (LCM–DIM). It is remarkable that regularly aligned step lines are clearly discerned in electrolyte solutions. The step lines observed by LCM–DIM are monatomic steps confirmed by scanning tunneling microscopy and atomic force microscopy. It is expected that LCM–DIM is a new powerful in situ method for the investigation of electrochemical reactions with the capability of atomic layer resolution.