title: Dynamics and spectroscopy of hydrogen atoms on Pd{111}.
abstract: Chemisorption of hydrogen on Pd{111} is a relatively simple, yet important surface chemical process. By using low-temperature scanning tunneling microscopy, tip-induced motion of adsorbed atomic hydrogen at 4 K has been observed at low coverage. The motion has been ascribed to excitation of vibrational modes that decay into translational modes; vibrational spectroscopy via inelastic electron tunneling corroborates this assignment, and the barrier to hydrogen atom motion has been determined. At higher coverages, tip-induced motion of vacancies in the hydrogen overlayer is observed, and the associated barrier has also been determined.
authors.affiliation: Departments of Chemistry and Physics, 104 Davey Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802-6300.
authors.forename: Luis C
authors.initials: LC
authors.lastname: Fernandez-Torres
authors.forename: E Charles H
authors.initials: EC
authors.lastname: Sykes
authors.forename: Sanjini U
authors.initials: SU
authors.lastname: Nanayakkara
authors.forename: Paul S
authors.initials: PS
authors.lastname: Weiss