SURFACE CHARACTERIZATION WITH SIMS: CARBON-MONOXIDE ADSORPTION ON NICKEL SURFACES
Abstract
The detection and mass selection of the secondary ions ejected from a solid as a result of ion bombardment form the basis of the Secondary Ion Mass Spectrometry (SIMS) technique. The purpose of the research presented in this thesis is to further our understanding of what information can be gained from the ejected secondary ions about the structure and chemical nature of the solid surface. To gain a detailed understanding of the SIMS process, a classical dynamics theoretical model of the ion bombardment event has been devised and is described in detail. Results of the calculations of ion bombardment of clean and reacted metal single crystal surfaces have yielded specific information about cluster ion formation mechanisms and atomic motion within the solid and have yielded a means by which experimental SIMS results can be correlated to real surface structures. In this thesis computational and experimental investigations of the chemisorption of CO on Ni(001) and stepped Ni(7 9 11) are presented. The results indicate that careful control of experimental parameters, such as the energy and angle of incidence of the primary ion, can result in cluster ions or ion yield variations which contain very specific information about the structure of the surface and the bonding geometry of adsorbates. An experimental SIMS study of the chemisorption of CO on Ni(111) yielded results which exhibited a definite sensitivity to changes in the CO overlayer structure, but these results clearly indicated that actual surface structure determinations with SIMS require concurrently performed theoretical investigations for comparison with the experiments.
Degree
Ph.D.
Subject Area
Analytical chemistry
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