title: Characterization of molybdenum carbide nanoparticles formed on Au(111) using reactive-layer assisted deposition.
abstract: Temperature programmed desorption (TPD), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM) have been used to characterize molybdenum carbide nanoparticles prepared on a Au(111) substrate. The MoC(x) nanoparticles were formed by Mo metal deposition onto a reactive multilayer of ethylene, which was physisorbed on a Au(111) substrate at low temperatures (<100 K). The resulting clusters have an average diameter of approximately 1.5 nm and aggregate in the fcc troughs located on either side of the elbows of the reconstructed Au(111) surface. Core level XPS shows that the electronic environment of the Mo and C atoms in the nanoparticles is similar to that found in Mo(2)C(0001) single crystals and carburized Mo metal surfaces. Peak intensities in XPS and AES spectra were used to estimate an average Mo/C atomic ratio of 1.2 +/- 0.3 for nanoparticles annealed above 600 K.
authors.forename: Jillian M
authors.initials: JM
authors.lastname: Horn
authors.forename: Zhen
authors.initials: Z
authors.lastname: Song
authors.forename: Denis V
authors.initials: DV
authors.lastname: Potapenko
authors.forename: Jan
authors.initials: J
authors.lastname: Hrbek
authors.forename: Michael G
authors.initials: MG
authors.lastname: White
mesh_terms: D000327:Adsorption; D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D005030:Ethylenes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling; D008982:Molybdenum / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D013499:Surface Properties; D013696:Temperature; D014965:X-Rays
chemical_list: D017554:Carbon Compounds, Inorganic; D005030:Ethylenes; D006046:Gold; D008982:Molybdenum; C036216:ethylene