This collection covers the physical and chemical phenomena of metal surfaces, including surface modifications and treatments. It is targeted at researchers working in materials science and also at newcomers to the research field of metal surfaces and surface analysis.

The Structure of Rare-Earth Metal Surfaces introduces the concepts of surface crystallography and surface-structure determination, outlines the principles of the most widely used experimental techniques and theoretical simulations, and reviews their application to the surfaces of rare-earth metals. In particular, the results of quantitative low-energy electron-diffraction experiments and multiple-scattering calculations are covered in some depth. The book is aimed at science graduates with an interest in surface crystallography. Contents: Introduction to the Rare Earths; The Basics of Surface Structure; Surface Structure Techniques; Crystal Growth and Surface Preparation; Rare-Earth Surface Science; Quantitative Low-Energy Electron Diffraction; Quantitative LEED Results; Summary OCo Past, Present and Future. Readership: Researchers in surface and interface science, crystallography, condensed matter physics and computational physics."

Imagine that a young physicist would approach a granting agen cy and propose to contribute to heterogeneous catalysis by studying the heat conductivity of gases in contact with a hot filament. How would he be received now? How would he have been treated sixty years ago ? Yet, more than sixty years ago, Irving Langmuir, through his study of heat transfer from a tungsten filament, uncovered most of the fundamental ideas which are used to-day by the scientific com munity in pure and applied heterogeneous catalysis. Through his work with what were for the first time "clean" metal surfaces, Langmuir formulated during a period of a little over ten years un til the early thirties, the concepts of chemisorption, monolayer, adsorption sites, adsorption isotherm, sticking probability, cata lytic mechanisms by way of the interaction between chemisorbed spe cies, behavior of non-uniform surfaces and repulsion between adsor bed dipoles. It is fair to say that many of these ideas constituting the first revolution in surface chemistry have since been refined through thousands of investigations. Countless papers have been pu blished on the subject of the Langmuir adsorption isotherm, the Langmuir catalytic kinetics and the Langmuir site-exclusion adsorp tion kinetics. The refinements have been significant. ThE original concepts in their primitive or amended form are used everyday by catalytic chemists and chemical engineers allover the world in their treatment of experimental data, design of reactors or inven tion of new processes.

The collisions of neutral or charged gaseous particles with solid surfaces govern many physical and chemical phenomena, as has been The gas/solid phenomena in turn depend on a recognized for a long time. great variety of processes such as the charge transfer of the gas/solid interface, adsorption and desorption, the energy transfer between an incident particle and the surface, etc. Our knowledge of these processes, however, is only fragmentary. This is partly due to the difficulty in adequately controlling the ex perimental conditions. Consequently, until recently the data were usually so complex that reliable information about a particular elementary process could not be deduced. Within the last five to ten years, however, the techniques of ultra-high vacuum and surface preparation have developed rapidly and there has been a booming and widespread interest in the role of gas/solid interactions in such diverse fields as plasma physics, thermonuclear reactions, thermionic energy conversion, ion propulsion, sputtering corrosion of the surface of satellites and ion engines, ion getter pumps, deposition of thin films, etc. This led to extensive investigations of numerous gas/solid phenomena, such as surface ionization, sputtering, emission of secondary electrons and ions from surfaces under atom and/or ion impact, ion neutralization, and the thermal accomodation of gaseous particles on surfaces. As a result, it has become possible to gather a variety of valuable information.

Using lasers to induce and probe surface processes has the advantages of quantum state specificity, species selectivity, surface sensitivity, fast time-resolution, high frequency resolution, and accessibility to full pressure ranges. These advantages make it highly desirable to use light to induce, control, or monitor surface chemical and physical processes. Recent applications of laser based techniques in studying surface processes have stimulated new developments and enabled the understanding of fundamental problems in energy transfer and reactions. This volume will include discussions on spectroscopic techniques, energy transfer, desorption dynamics, and photochemistry.

Using lasers to induce and probe surface processes has the advantages of quantum state specificity, species selectivity, surface sensitivity, fast time-resolution, high frequency resolution, and accessibility to full pressure ranges. These advantages make it highly desirable to use light to induce, control, or monitor surface chemical and physical processes. Recent applications of laser based techniques in studying surface processes have stimulated new developments and enabled the understanding of fundamental problems in energy transfer and reactions. This volume will include discussions on spectroscopic techniques, energy transfer, desorption dynamics, and photochemistry.

Ionization on hot tungsten, tantalum, and rhenium surfaces was studied. An atomic beam of neutral atoms effused from a Knudsen-type effusion vessel and struck a hot filament of the metal being studied. A temperature- dependent fraction of these atoms was ionized. This filament served as the ion source of a 60-degree-sector single-directional focusing mass spectrometer. According to the Saha-Langmuir theory of surface ionization the temperature dependence of ionization is related to the difference between the ionization potential of the impinging atom and the work function of the surface under consideration.