AVS 53rd International Symposium
    Surface Science Tuesday Sessions
       Session SS1-TuM

Paper SS1-TuM10
Deposition and Reactivity of Mo@sub x@S@sub y@ (x/y=4/6, 6/8, 7/10) Clusters on Au(111)

Tuesday, November 14, 2006, 11:00 am, Room 2002

Session: Reactivity of Metal Clusters
Presenter: J.M. Lightstone, Stony Brook University
Authors: J.M. Lightstone, Stony Brook University
M.J. Patterson, Stony Brook University
J. Lofaro, Stony Brook University
P. Liu, Brookhaven National Laboratory
M.G. White, Brookhaven National Laboratory
Correspondent: Click to Email
We have recently constructed a cluster deposition apparatus which employs a magnetron sputtering source for generating gas-phase cation clusters of pure metals and metallic compounds. Our current focus has been the production of early transition metal sulfide clusters for reactivity studies in both the gas-phase and deposited on well defined surfaces. The transition metal sulfides are particularly interesting due to their catalytic properties@footnote 1@ and their ability to form fullerene-like nanostructures that reflect the S-M-S layered structure of the bulk materia.l@footnote 2@ The work reported here examines preliminary electron spectroscopy and temperature programmed desorption results from size-selected Mo@sub x@S@sub y@ (x/y=4/6, 6/8 and 7/10) clusters deposited on a Au(111) single crystal. A wide array of molybdenum sulfide clusters, Mo@sub x@S@sub y@@super +@ (x/y= 2/6, 3/7, 4/6, 5/7, 6/8, 7/10, 8/12), were generated using a magnetron sputtering source, including the "magic" number species Mo@sub 4@S@sub 6@@super +@. Several Mo@sub x@S@sub y@@super +@ clusters were mass selected using a quadrupole mass spectrometer and deposited on a Au(111) single crystal under ultra-high vacuum conditions. The presence of deposited clusters was confirmed using Auger Spectroscopy (AES) while Ultraviolet and X-Ray Photoelectron Spectroscopy (UPS, XPS) were used to probe the electronic structure of the cluster covered surface. Temperature Programmed Desorption (TPD) of carbon-13 labeled CO shows cluster-dependent desorption peaks which were used to estimate CO binding energies. The TDP spectra are also found to depend on annealing temperature, which suggest surface modifications or cluster decomposition at higher temperatures. @FootnoteText@ @footnote 1@T. R. Thurston and J. P. Wilcoxon, J. Phys. Chem. B, 103 (1997) 11.@footnote 2@R. Tenne and C. N. R. Rao, Phil. Trans. R. Soc. Lond. A, 362 (2004) 2099.