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This work is supported by the European Union in the scope of the SURMOF project under which this work was undertaken (contract number STRP 032109) ; The room temperature deposition of copper onto a Au(111)-(22×√3) reconstructed surface has been investigated using scanning tunnelling microscopy (STM), up to a copper coverage of approximately 0.7 monolayer (ML). At extremely low coverage (~0.02 ML), preferential adsorption is observed to occur by displacement of gold atoms and incorporation of copper into the top gold layer at alternate herringbone elbows along the langle112rangle directions. Both fcc regions and hcp regions are occupied. With increasing coverage, incorporation of copper continues but copper is also deposited on top of the incorporated copper islands. When full coverage of these islands to monolayer thickness is reached, further deposition leads to preferential growth of those islands located in hcp regions through both the deposition process and migration of copper from other elbows, predominantly those in fcc regions. Eventually, a critical island size is reached above which atomically thick copper islands exhibit a reconstructed surface similar, in essence, to that of the clean gold surface. Models for the initial adsorption mechanism, island formation and the eventual reconstruction of the copper islands are discussed qualitatively in terms of surface strain within the gold and copper surfaces. ; Publisher PDF ; Peer reviewed

The Engineering and Physical Sciences Research Council (EPSRC) is acknowledged for the funding of FG (EP/M029077/1) and RM (EP/506631/1). FG also acknowledges the European Union for funding the SURMOF project under which part of this work was undertaken (contract number NMP4-CT-2006-032109). ; The structure and surface chemistry of ultrathin metallic films of one metal on another are strongly influenced by factors such as lattice mismatch and the formation of near-surface alloys. New morphologies may result in modified chemical properties which in turn open up different routes for molecular adsorption, desorption and surface functionalization, with important consequences in several fields of application. The Cu/Au(111) system has received the attention of many studies, only a few however have been performed in ultra-high vacuum (UHV), using surface sensitive techniques. In this contribution, the room temperature deposition of copper onto the (22×√3)-Au(111) surface, from submonolayer to thick film, is investigated using scanning tunnelling microscopy (STM). The onset of copper adsorption is seen to occur preferentially at alternate herringbone elbows, with a preference for hcp sites. With increasing coverage, copper-rich islands exhibit a reconstructed surface reminiscent of the clean Au(111) herringbone reconstruction. Disordered, pseudo-ordered and ordered surface layers are observed upon annealing. Models for the initial adsorption/incorporation mechanism, formation of adlayers and evolution with increasing coverage and annealing are qualitatively discussed. Further, the reactivity of copper-doped Au(111) systems is considered towards the adsorption of organic molecules of interest in nanotechnology and their catalytic applications. ; Publisher PDF ; Peer reviewed

Funding: Scottish Government ; A dihydro-TTF derivative with four acetyl-protected thiol ligands was synthesised and adsorbed on Au(111) under UHV conditions. Scanning Tunnelling Microscopy (STM) and Infrared (IR) spectroscopy show that self-organised structures are formed following annealing to 333 K, with each pair of bidentate thiolate ligands bonding to a single gold adatom in a S–Auad–S complex. Due to the lack of a direct orbital overlap between the dihydro-TTF moieties and the surface, relatively little charge transfer between TAT-TTF and the gold surface occurs. ; Publisher PDF ; Peer reviewed