Tip-induced nanostructuring of a clean and ethene-modified Pt(111) electrode with Cu

The adlayer formed when ethene is adsorbed from sulfuric acid solution on a Pt(111) electrode at room temperature has a disordered structure. Small domains with local ordering are discernible by STM. The adsorbate is not (or only to a minor extent) displaced by Cu-UPD. Scanning the surface in a very small area with the tip very closely approached to the surface leads to displacement of the organic adsorbate followed by Cu-UPD. Scanning under similar conditions over the surface free of the organic adsorbate, but covered by UPD-Cu also leads to a nanostructuring of the surface. Structures of sizes down to 5 nm can be fabricated by this kind of nanolithography. The results are interpreted by a local, tip-induced alloy formation.