Surface structure

In this chapter we will consider the structures of surfaces of condensed phase objects comprised of constituent particles of atoms, inorganic groups and molecules or molecular groups (collectively termed particles for convenience. In learning about surface structure, it is convenient to start with ordered surfaces since these are the most amenable to quantitative characterization. With this in hand we can form the basis for understanding the properties of many important crystalline materials surfaces such as those of catalytically active transition metals and semiconductors such as silicon used in electronic devices. There are two main cases of interest for physical surface structure: 1.) bare surfaces, which are defined as the termination of the substance in vacuum, and 2.) overlayers of another substance, typically a single layer of atoms or small molecules, either physisorbed or chemisorbed. These classifications can be broken down further in terms of the differences between the ordering in the top surface layer (at the ambient interface) and the bulk.