COLL 167 |
| Luis C. Fernández-Torres, E. Charles H. Sykes, Patrick Han, Sanjini U. Nanayakkara, and Paul S. Weiss. Departments of Chemistry and Physics, The Pennsylvania State University, 152 Davey Lab, University Park, PA 16802-6300 |
| The interaction of hydrogen with Pd{111} has been investigated with low temperature scanning tunneling microscopy and spectroscopy. Palladium is unique in its ability to both adsorb and absorb hydrogen. Adsorption of low exposures of hydrogen has allowed for the observation of tip-induced hydrogen atom diffusion at 4 K. The diffusion of atomic hydrogen at 4 K has been ascribed to inelastic tunneling of electrons; inelastic electron tunneling spectroscopy (IETS) corroborates this assignment, and the hydrogen atom diffusion barrier has been determined. Adsorption of high exposures of hydrogen results in formation of two ordered overlayer structures: (1x1)-H and (√3x√3)-2H. Absorption of hydrogen into subsurface sites in Pd, concurrent with H diffusion from the bulk, have been attributed as the predominant reasons for two observed phenomena: tip-induced vacancy ordering, and Pd{111} lattice distortion. |
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Posters: Fundamental Research in Surface and Colloid Chemistry
6:00 PM-8:00 PM, Monday, August 23, 2004 Pennsylvania Convention Center -- Hall C, Poster
Division of Colloid and Surface Chemistry |