During the last decade, surface research has clearly shifted its interest from the macroscopic to the microscopic scale; a wealth of novel experimental techniques and theoretical methods have been applied and developed successfully. The Topics volume at hand gives an account of this tendency. For the understanding of surface phenomena and their exploitation in tech­ nical applications, the theoretical and experimental analysis at the microscopic level is of particular interest. In heterogeneous catalysis, for example, a chemical reaction takes place at the interface of two phases, and the process occurring at the surface is composed of a sequence of individual microscopic steps. These individual steps include adsorption, desorption, surface diffusion, and reaction on the surface. These elementary steps are greatly influenced by the structure and the dynamics of the surface region. Especially the catalytic activity may strongly depend on the structure of the catalyst's surface. The necessity of per­ forming surface investigations on a microscopic scale is also reflected clearly in research work relating to metal-semiconductor interfaces which determine es­ sentially the properties of electronic device materials. The experimental probe on the atomic scale, coupled with parallel theoretical calculations, showed that the electronic properties of a metal-semiconductor interface strongly depend on the crystallographic structure of the semiconductor; in particular, it is im­ portant to know in this context the modification of the atomic arrangement in the surface region caused by the termination of the crystal by the surface.

1. Introduction: The Relevance of the Structure and Dynamics of Surfaces.- 1.1 Structure of Surfaces.- 1.2 Dynamics of Surfaces.- 1.3 Conclusion and Outlook.- References.- 2. Experimental Methods for Determining Surface Structures and Surface Corrugations..- 2.1 Basic Physical Principles.- 2.2 Notation and Conventions.- 2.3 Surface Diffraction from Regular Gratings.- 2.4 Other Methods Based on Diffraction Effects.- 2.5 Microscopy Techniques with Atomic Resolution.- 2.6 Ion Scattering Spectroscopy (ISS).- 2.7 Other Methods.- 2.8 Outlook.- References.- 3. High-Resolution Electron Microscopy of Surfaces.- 3.1 Background.- 3.2 Image Formation.- 3.3 Applications.- 3.4 A Note of Warning.- 3.5 Gold(110).- 3.6 Other High-Resolution Techniques.- 3.7 Conclusions and the Future.- References.- 4. Surface Channeling and Its Application to Surface Structures and Location of Adsorbates.- 4.1 Overview.- 4.2 Principles.- 4.3 Surface Channeling Angular Yield Profiles.- 4.4 Applications.- 4.5 Applicability of Surface Channeling to Surface Studies.- 4.6 Factors of Influence on the Angular Yield Profiles.- 4.7 Concluding Remarks.- References.- 5. Dynamical Surface Properties in the Harmonic Approximation..- 5.1 Introductory Remarks.- 5.2 The Theory of Vibrations in the Harmonic Approximation.- 5.3 Bare Metals.- 5.4 Metals with Adsorbates.- 5.5 Concluding Remarks.- References.- 6. Molecular Dynamics and the Study of Anharmonic Surface Effects..- 6.1 Introductory Remarks.- 6.2 Analysis of Many-Particle Systems.- 6.3 Average Values.- 6.4 Molecular Dynamics Systems.- 6.5 Applications of the Molecular Dynamics Method.- 6.6 Final Remarks.- References.- 7. Surface Phonon Dispersion of Surface and Adsorbate Layers.- 7.1 Background and Overview.- 7.2 Description of the Experiment.- 7.3 Phonon Dispersion Curves.- 7.4 Internal Strains, Phonon Anomalies and Reconstruction.- References.