Scanning tunneling microscope-induced modification of Ag films and nanowire arrays on Cu(100) surfaces

Abstract

We demonstrate the ability to use scanning tunneling microscopy to create nanometer-scale pits on Ag films grown on Cu(100) substrates. Atomic resolution images show that the Ag structures are intact within these pits. We also demonstrate how we can selectively modify segments of Ag nanowire arrays grown on atomic nitrogen modified Cu(100) surfaces.

Scanning tunneling microscopy and photoemission studies of self-organised Ag nanostructures on the N-modified Cu(001) surface

“…Also the early growth (up to 2 ML) of Ag on N modified Cu(001) was reported in the past by STM [1,33]. It was shown [34] that the growth of Ag in this case proceeds in the same guise as on the clean Cu(001) surface, i.e., with a c(2x10) periodicity for the first layer of Ag growing on clean Cu and forming an unreconstructed Ag(111) layer for Ag stripes of higher thickness. In this paper we consider much higher coverage values than previously reported and the whole sequence of Ag overlayers is here discussed.…”

“…2c) we cannot give evidence of this process. At higher thickness the Ag overlayer grows as unreconstructed Ag(111) [34,46]. Also the early growth (up to 2 ML) of Ag on N modified Cu(001) was reported in the past by STM [1,33].…”

“…This peculiarity in the N overlayer is rarely found and it is reported here as an example. determines a growth of Ag in the shape of a quasi hexagonal c(2x10) structure [34,35,45,46]. Note that room temperature Cu(001)-Ag alloying, confined to the 2D surface, was predicted for very low Ag coverages (Θ Ag <0.13 ML) [47].…”

“…Ag nanostructured films on N-modified Cu surfaces were investigated, for low Ag coverage, with STM, showing the possibility of creating single crystal Ag nanowires on sub-saturated c(2x2)-N/Cu(001). The Ag nanowires formed on the bare Cu areas between the arrays of N islands and are therefore aligned along the <100> direction, up to 4 atomic layers thick [1,34]. The growth of Ag on the bare Cu areas followed the same evolution as the formation of Ag ultrathin films on clean Cu(001), with formation for low coverage of a c(10x2) superstructure, followed by a simple pseudoexagonal overlayer structure [35].…”

Kinetic hindrance during the surface oxidation of Cu(100)–c(10×2)-Ag

“…[23][24][25] The STM study of Sprunger et al 23 concluded that at subsaturation coverages Ag forms a layer-confined surface alloy even at temperatures as low as 300 K. It was found that only ϳ0.13 ML of Ag can be alloyed into the Cu͑100͒ surface. At higher Ag coverages, pseudohexagonal c͑10ϫ 2͒-Ag patches condense within the Cu͑100͒ surface layer.…”