Low-energy electron diffraction for surface structure analysis

Abstract

Low-energy electron diffraction (LEED) is the most important technique for studying the atomic structures of crystalline surfaces. This review aims to give an introduction into the experimental, theoretical and analytical procedures needed for a successful structure determination. After a brief introduction that gives some historical background and sets the problem in perspective, the experiment is described. The fundamentals of two-dimensional crystallography are discussed and their application to LEED are described. The calculation of diffracted intensities requires the development of N-beams dynamical theory, which is discussed together with the need for appropriate computer programs. Since the analysis is based on trial-and-error methods some attention is paid to the development of structure models, the problems caused by the co-existence of equivalent domains, and the procedures for evaluating the postulated models. A brief discussion of the accomplishments is given which, rather than comprehensive, is an assessment of the present state of the art in surface crystallography.