Dynamics of Gas-Surface Scattering deals with the dynamics of scattering as inferred from known properties of gases and solids. This book discusses measurements of spatial distributions of scattered atomic and molecular streams, and of the energy and momentum which gas particles exchange at solid surfaces. It also considers two regimes of scattering, both of which are associated with a lower range of incident gas energies: the thermal and structure scattering regimes. Comprised of 10 chapters, this book opens with a brief historical overview of the early experiments that investigated the dynamics of scattering of gases by surfaces. The discussion then turns to some elements of the kinetic theory of gases; intermodular potentials and interaction regimes; and classical-mechanical lattice models used in gas-surface scattering theory. The applications of molecular beams to the study of gas-surface scattering phenomena are also described. The remaining chapters focus on experiments and theories on scattering of molecular streams by surfaces of solids, with emphasis on thermal and structure regimes of inelastic scattering; quantum theory of gas-surface scattering; and quantum mechanical scattering phenomena. This text concludes with an analysis of energy exchange processes that may occur when a solid surface is completely immersed in a still gas. This monograph will be a valuable resource for students and practitioners of physics, chemistry, and applied mathematics.

This monograph deals with the kinetics of adsorption and desorption of molecules physisorbed on solid surfaces. Although frequent and detailed reference is made to experiment, it is mainly concerned with the theory of the subject. In this, we have attempted to present a unified picture based on the master equation approach. Physisorption kinetics is by no means a closed and mature subject; rather, in writing this monograph we intended to survey a field very much in flux, to assess its achievements so far, and to give a reasonable basis from which further developments can take off. For this reason we have included many papers in the bibliography that are not referred to in the text but are of relevance to physisorption. To keep this monograph to a reasonable size, and also to allow for some unity in the presentation of the material, we had to omit a number of topics related to physisorption kinetics. We have not covered to any extent the equilibrium properties of physisorbed layers such as structures, phase tr- sitions and thermodynamic properties in general. A number of excellent revIew articles, listed in the bibliography, cover this material. Likewise, little is said about scattering off solid surfaces; this subject is again covered in several books and many review articles. Lastly, little is said about chemisorption kinetics, for which microscopic thebries and models have not been fully developed but are still at a rather early exploratory stage.

Interface phenomena are most fascinating because of the mixing of different scales and the interference of diverse physical processes. This makes it necessary to use different levels of description: microscopic, kinetic, and gas-dynamical. A unified quasiclassical approach is used to answer practical questions dealing with inelastic gas-surface scattering, the kinetics of adsorption layers, the evolution of inhomogeneities and defects at the surface, the Knudsen layer, the development of boundary conditions on the kinetic and gas-dynamical levels, the determination of exchange and slip coefficients, and so on.

There is considerable interest, both fundamental and technological, in the way atoms and molecules interact with solid surfaces. Thus the description of heterogeneous catalysis and other surface reactions requires a detailed understand ing of molecule-surface interactions. The primary aim of this volume is to provide fairly broad coverage of atoms and molecules in interaction with a variety of solid surfaces at a level suitable for graduate students and research workers in condensed matter physics, chemical physics, and materials science. The book is intended for experimental workers with interests in basic theory and concepts and had its origins in a Spring College held at the International Centre for Theoretical Physics, Miramare, Trieste. Valuable background reading can be found in the graduate-Ievel introduction to the physics of solid surfaces by ZangwilI(1) and in the earlier works by Garcia Moliner and F1ores(2) and Somorjai.(3) For specifically molecule-surface interac tions, additional background can be found in Rhodin and Ertl(4) and March.(S) V. Bortolani N. H. March M. P. Tosi References 1. A. Zangwill, Physics at Surfaces, Cambridge University Press, Cambridge (1988). 2. F. Garcia-Moliner and F. Flores, Introduction to the Theory of Solid Surfaces, Cambridge University Press, Cambridge (1979). 3. G. A. Somorjai, Chemistry in Two Dimensions: Surfaces, Cornell University Press, Ithaca, New York (1981). 4. T. N. Rhodin and G. Erd, The Nature of the Surface Chemical Bond, North-Holland, Amsterdam (1979). 5. N. H. March, Chemical Bonds outside Metal Surfaces, Plenum Press, New York (1986).

A theory of gas surface interaction should predict the distribution of molecules re-emitted from a surface in function of the properties of the incident flux and the physics of the surface. It depends on our uncertain knowledge of free-bound heterogeneous molecule interactions and our equally uncertain knowledge of atomic lattice dynamics. The paper critically summarizes and compares with experimental results an increasingly detailed lattice model which gives plausible energy exchange predictions and a geometrical (hard cube) model which shows promise as a correlator of data on scattering direction distribution. Both these models are based on classical interaction mechanisms; some potential generalizations to quantum models are suggested. (Author).