Accession Number : ADA258578
Title : Vibrational Spectroscopic Studies of Adsorbates on Bimetallic Surfaces.
Descriptive Note : Doctoral thesis
Corporate Author : TEXAS A AND M UNIV COLLEGE STATION DEPT OF CHEMISTRY
Personal Author(s) : Kuhn, William K
Report Date : Dec 1992
Pagination or Media Count : 163
Abstract : In this work, well-defined bimetallic surfaces have been studied using carbon monoxide adsorption in conjunction with infrared reflection absorption spectroscopy (IRAS). These studies have indicated that for CO adsorbed on Cu overlayers, the bond between the CO and the Cu adatoms is comprised of both pi-back-donation and polarization interaction components. The sum of the contributions from these effects determines the observed bond strength with the observed CO stretching frequency being determined by the relative contributions of the components. In addition, it was determined that IR spectra of adsorbed CO show a remarkable sensitivity to surface structure. Three-dimensional Cu clusters, well-ordered two dimensional Cu islands and isolated Cu atoms are distinctively characterized by their CO IR peaks. In addition, both disorder-order and order-order transitions are observed for the metal overlayers on the single crystal metal substrates. It was also observed that localized segregation and ordering of mixed Co and S overlayers on a Mo(110) substrate occurs upon annealing.
Descriptors : *METALS , *SPECTROSCOPY , *SURFACES , *ADSORBATES , ANNEALING , STRUCTURES , SINGLE CRYSTALS , SUBSTRATES , REFLECTION , THREE DIMENSIONAL , SORPTION , TANTALUM , CARBON MONOXIDE , SULFUR , SURFACE CHEMISTRY , TRANSITIONS , NICKEL , COPPER , SPECTRA , RHODIUM , ADATOMS , ADDITION , MONOXIDES , COBALT , CHEMICAL BONDS , SENSITIVITY , CRYSTALS , MOLYBDENUM , THESES , TWO DIMENSIONAL , VIBRATION
Subject Categories : Inorganic Chemistry
Properties of Metals and Alloys
Atomic and Molecular Physics and Spectroscopy
Distribution Statement : APPROVED FOR PUBLIC RELEASE