Atomic and Ionic Impact Phenomena on Metal Surfaces: (25 Struktur und Eigenschaften der Materie in Einzeldarstellungen)

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.

Table of Contents:
1. The Nature of the Metal Surface.- 1.1. The Heterogeneous Surface.- 1.2. Theoretical Description of Metal Surfaces. The Work function.- 2. Determination of the Work Function of Metal Surfaces.- 2.1. Thermal Emission of Electrons.- 2.2. Thermal Emission of Ions.- 2.3. Photoelectric Method.- 2.4. Method Based on the Field Emission of Electrons.- 2.5. Measurements of Contact Potential.- 2.6. Electron Reflection Method.- 3. Preparation of Metal Surfaces.- 3.1. Thermal Desorption; the Flash-Filament Method.- 3.2. Ion Bombardment of the Surface.- 3.3. Evaporation of Thin Layers.- 3.4. Galvanotechnic Procedures.- 4. Binding Forces Effective in the Collision of Atoms and Molecules with Metal Surfaces.- 4.1. vanderWaals Forces—Physical Adsorption.- 4.2. Exchange Forces—Weak Chemisorption on Homogeneous and Heterogeneous Surfaces.- 4.3. Heteropolar Binding Forces—Strong Chemisorption.- 5. Energetics of Surface Reactions.- 5.1. General Remarks and Definitions.- 5.2. Heats of Adsorption for Physical Adsorption.- 5.3. Heats of Adsorption for Weak Chemisorption.- 5.4. Heats of Adsorption for Strong Chemisorption.- 6. Inelastic Collisions of Atoms and Molecules with Metal Surfaces: The Accommodation Coefficient.- 6.1. Definition and General Remarks.- 6.2. Methods for Measuring Accommodation Coefficients.- 6.3. Experimental Results on Accommodation Coefficients.- 6.4. Determination of Relaxation Times for the Process of Energy Exchange between the Normal Vibrational States of the System Comprising Adsorbed Molecule and Metal Surface.- 7. Elastic Collisions of Atoms and Molecules with Metal Surfaces.- 8. Emission of Positive Ions Formed at Metal Surfaces (Surface Ionization).- 8.1. Theoretical Considerations.- 8.2. Relation of the Saha-Langmuir Equation to the Frenkel Equationand to Charge-Transfer Probabilities.- 8.3. Experimental Investigation of Positive Surface Ionization (PSI).- 9. Formation and Emission of Negative Ions at Metal Surfaces (NSI).- 9.1. Theoretical Considerations.- 9.2. Experimental Methods.- 9.3. Experimental Results.- 10. Sputtering of Metal Surfaces by Ion Bombardment.- 10.1. Introduction.- 10.2. Experimental Methods.- 10.3. Experimental Results.- 10.4. Theoretical Treatments of the Sputtering Process.- 11. Ion Scattering from Metal Surfaces.- 11.1 Definitions: Ion-Reflection Coefficient and Secondary-Emission Coefficient.- 11.2 Experimental Techniques.- 11.3. Experimental Ion-Reflection and Secondary-Emission Coefficients.- 11.4. Theoretical Treatment of Ion Scattering from Metal Surfaces.- 12. Neutralization of Ions on Metal Surfaces (Potential Emission of Secondary Electrons).- 12.1. Introductory Remarks and Definitions.- 12.2. Auger Neutralization; Resonance Neutralization.- 13. De-excitation of Metastable Atoms and Ions on Metal Surfaces.- 13.1. Introductory Remarks and Description of Experimental Methods.- 13.2. Experimental Data for the Total Yield and Energy Distribution of Secondary Electrons from De-excitation of Metastable Atoms and Ions on Metal Surfaces.- 13.3. Theoretical Aspects of the Auger De-excitation of Metastable Atoms on Metal Surfaces.- 14. The Emission of Electrons from Metal Surfaces by Bombardment with Charged and Uncharged Particles (Kinetic Emission).- 14.1. Introduction.- 14.2. Experimental Methods.- 14.3. Experimental Results.- 14.4. Theoretical Aspects of the Kinetic Emission of Secondary Electrons.- Literature.- Author Index.