We use scanning tunneling microscopy (STM) and core and valence photoemission as well as low-energy electron diffraction to characterize recently discovered S/Cu(111) surface structures that appear at low coverage below ordering temperatures of around 230 K. At even lower coverage ordered local arrangements are observed near steps and dislocations. Of the laterally extending structures one is open. and honeycomb (hc) like, while three other structures (I,II,III) are more complicated. It is suggested that the structures can be explained as reordered (0001) planes of CuS. Surprisingly the open hc structure gives room for the Cu(111) surface state according to photoemission and scanning tunneling spectra. Core level spectra provide support for one of the models proposed for an earlier studied room-temperature structure [Cu(111)-( root 7x root7)R+/-19.1 degrees -S].

Metallic nanowires of cobalt, copper, and iron oxide magnetite (Fe3O4) have been synthesized within the pores of mesoporous silica using a supercritical fluid inclusion technique. The mesoporous matrix provides a means of producing a high density of stable, hexagonally ordered arrays of highly crystalline nanowires. The formation of the metal and metal oxide nanowires within the silica mesopores was confirmed by transmission electron microscopy (TEM), N-2 adsorption experiments, and powder X-ray diffraction (PXRD). The mechanism of nanowire formation within the mesopores appears to occur through the initial binding and coating of the pore walls with the metal atoms to form tubelike structures within the mesoporous template. The thickness of these tubes subsequently increases with further metal deposition until nanowires are formed. Additionally, the crystal structure of the cobalt nanowires formed within the mesoporous template can be readily changed by manipulating the density of the supercritical fluid phase.