Charles B. Duke

Surface science : the first thirty years

Paperback. To commemorate the thirtieth anniversary of the founding of Surface Science and to honour Harry Gatos, founder and editor of the journal for twenty-eight years, this book has been compiled.It consists a collection of short (less than ten pages) articles describing the historical development in the years 1964-92 of selected topics in surface science providing an overview of the field, and indicating its future direction. Approximately eighty prominent surface scientists have contributed historical and technical reviews covering a wide range of topics. Many contributions are personal accounts of the evolution of the work in the laboratories/industries where the authors have worked.

The atomic geometry of GaAs(110) revisited

Improvements in surface structure determination methodologies based on the analysis of experimental low-energy electron diffraction intensities are utilized to perform an R-factor structure determination for GaAs(110). In addition to the commonly-accepted structure (a top-layer bond-length-conserving rotation of the As outward and the Ga inward characterized by ω1 = 27°, relaxation of the top layer toward the bulk by 0.05 A, and a relaxation of the second-layer Ga outward and As inward by 0.06 A), a new structure is found which consists of a top-layer bond-length-conserving rotation of ω1 = 7°, relaxation of the top layer away from the bulk by 0.05 A, and a converse second-layer relaxation of the Ga and As by 0.03 A. This new structure may be distinguished from the accepted one and refinements thereof by examining the integrated intensities of the diffracted beams. When these are considered, a refinement of the accepted structure still provides the best description of measured low-energy electron diffraction intensity data, and is manifestly compatible with other recent analyses of photoemission and isochromat data.

Epitaxial growth of fcc Fe on Cu(100)

Abstract Layer-by-layer epitaxial growth of Fe on Cu(100) is reported. The epitaxy is characterized using Auger electron spectroscopy and low energy electron diffraction intensity analysis. Good quality epitaxial Fe films having thicknesses ranging from one to four monolayers are stabilized by the Cu(100) substrate. The overlayer structure is shown to be nearly identical to a continuation of the fcc lattice of the substrate.

Polymers and molecular solids: New frontiers in surface science

Abstract A brief review is given of the present state of knowledge of the surface properties of polymers and molecular solids. These materials are shown to exhibit surface phenomena which are dramatically different from those characteristic of metals and covalent solids. The origin of these differences resides in the combined occurrence both of large electronic and atomic polarizabilities and of small probabilities for the transfer of an electronic excitation from one molecular site to another. The interplay of these two quantities leads to a diversity in the character of the resulting electronic excitations, ranging from localized molecular ion states in aromatic pendant-group polymers to quasi-one-dimensional metallic behavior in certain charge transfer salts and polymers. The primary role of the surface in such materials is the introduction of large, inhomogeneous fluctuations in the relaxation energies associated with the polarization of the solid by an excitation. These fluctuations produce a number of novel phenomena including localized surface states in the absence of dangling bonds, inhomogeneous broadening of photo-emission spectra, and alterations of the charge state of surface molecules. A simple, unified theoretical framework is developed for the interpretation of these phenomena.

The surface science of xerography

Over the past four decades xerography, the dry ink marking process developed by the photocopy industry, has grown from nothing into a

Surface structure determination by low-energy electron diffraction☆

170 billion industry worldwide. This amazing commercial success is due to the fact that during this period, xerographic technology experienced constant and often-dramatic improvement created by sustained industrywide research and development. Indeed, the development of the xerographic copying and printing industry is one of the great applied surface science successes of all time. In this article we outline the story of the advances in xerographic technology during the past four decades, describe the profound dependence on these advances of the control of surface and interface properties of increasingly sophisticated multi-component materials systems, and indicate the potential impact on the industry of the continuing development of the surface and interface science of the multi-component materials packages used in xerographic technology.

LDP Lean Document Production---O.R.-Enhanced Productivity Improvements for the Printing Industry

The reflection of an incident «low-energy» (10 eV≲E≲≲500 eV) electron by a solid is dominated by the consequences of its interactions with the valence electrons in the solid. In particular, the high probability that the incident electron suffers an inelastic electron-electron collision renders the elastic electron-solid scattering cross-sections direct measures of the electronic structure and positions of ion cores within 10 A or less of the solid’s surface. We indicate the major features of the coherent reflection,i.e. diffraction, of such low-energy electrons from planar surfaces of single-crystal solids and of current theoretical models of this phenomenon. Emphasis is placed on those features of the electron-electron and electron-ion-core interactions which permit the extraction of the atomic geometry of surface species from measured low-energy electron diffraction (LEED) intensities. Analysis of the elastic low-energy electron diffraction intensities from the low-index faces of aluminum reveals the relatively modest influence on these intensities of the detailed shape of the one-electron optical potential and of the electronic structure of the ion cores. This result, in turn, is used to analyse the atomic structure of Ni(100)-c(2×2)-S, Ni(100)-c(2×2)-O and Cu(100)-c(2×2)-O adsorbed overlayers. Finally, we indicate the present status of applications of LEED intensity analyses to determine the atomic geometry of periodic surface structures.

Energy-dependent exchange potentials in low-energy electron diffraction from GaAs(110)

Xerox has invented, tested, and implemented a novel class of operations-research-based productivity-improvement offerings, trademarked LDP Lean Document Production® solutions, for the

Surface structure determination by low-energy electron diffraction

100 billion printing industry in the United States. These solutions, which Xerox has implemented in approximately 100 sites to date, have provided dramatic productivity and cost improvements for both print shops and document-manufacturing facilities, as measured by reductions of 20--40 percent in revenue-per-unit labor cost. They have generated approximately

The surface geometry of GaAs(110): A response

200 million of incremental profit across the Xerox customer value chain since their initial introduction in 2000. The offerings have extended the use of operations research to small-and medium-sized print shops, while increasing the scope of its application to large document-production facilities.