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Author Ma, Q. ♦ Rosenberg, R. A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ GRAPHITE ♦ TITANIUM ♦ CHEMICAL BONDS ♦ PHOTOELECTRON SPECTROSCOPY ♦ ADSORBENTS ♦ VAN DER WAALS FORCES ♦ CHEMICAL REACTIONS ♦ LAYERS ♦ DIFFUSION ♦ SURFACE PROPERTIES
Abstract The nature of the interaction between highly oriented pyrolitic graphite (HOPG) and adsorbed Ti is examined by soft x-ray photoelectron spectroscopy. By monitoring the C 1s signal, it is found that Ti does not chemically bond to, but only interacts through the Van der Waals force with, a pristine HOPG surface. Time-dependent variations in the C 1s peak intensity are interpreted in terms of diffusion of adsorbed Ti atoms, which results in the formation of clusters. This behavior is further evidence for a weakly adsorbed overlayer and implies that this surface is {ital a priori} unable to support a layer-by-layer growth. A chemical reaction occurs only when oxygen is incorporated or defects are present. The presence of adatoms on HOPG has an effect on the screening process of the HOPG C 1s core hole, which can be detected even at the Van der Waals interaction level. This may be used as a measure of the strength of interfacial interactions, especially for cases of weak or small-scale interactions. {copyright} {ital 1999} {ital The American Physical Society}
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1999-07-01
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 60
Issue Number 4


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