AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP23
The Periodically-Stepped NiO(100) Surface and the Adsorption of Bromobenzene

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Surface Science Poster Session
Presenter: S. Chapman, University of Nebraska-Lincoln
Authors: S. Chapman, University of Nebraska-Lincoln
M.A. Langell, University of Nebraska-Lincoln
Correspondent: Click to Email
Periodically-stepped NiO(100) was prepared and characterized the surface with Low Energy Electron Diffraction, (LEED), Auger Electron Spectroscopy, (AES), and X-Ray Photoelectron Spectroscopy, (XPS) to model surface defects relevant to heterogeneous chemical processes. All solid materials, including single crystal surfaces, possess irregular steps and other defects. These step defects, model undercoordinated sites that initialize catalytic and other chemical behavior. The NiO(100) single crystal was cut, polished, and oriented with regular repeating steps of seven-atom terrace width. LEED diffraction patterns are characteristic of an ordered step array with appropriate terrace and step height dimensions. Preliminary results show bromobenzene adsorbs onto stepped NiO(100) surface at 133K. The XP spectra of 515L of the adsorbate give two distinct carbon peaks separated by 4.5eV and the Ni 2p region peaks exhibit minimal structure loss. Thermal Desorption Spectrometry, (TDS), shows the majority of physisorbed bromobenzene desorbing molecularly by 190K and smaller adsorbed ring fragments around 280K. Studying a surface of characterizable defects of known density helps further the understanding of the first initial steps occurring in a chemical reaction and in the fabrication of nanostructure materials.