Monolayer Surface Structures

This chapter focuses on the structures of surfaces at the atomic scale. Almost half of the detailed surface structures known have been obtained from the dynamical analysis of low-energy electron diffraction data from single-crystal surfaces. Vibrational spectroscopy has also made a significant contribution to the understanding of surface bonding of monolayers and how molecules rearrange on surfaces. The chapter introduces a description of the structures of clean surfaces and how surface atoms exhibit different properties from their bulk counterparts through the concepts of surface relaxation and reconstruction. Atoms and ions may be used as probes of surface structure. Atomic diffraction from a surface can also provide surface structural information. Direct observations of surface structure have been obtained through developments in the scanning probe microscopies (SPM). These advances in SPM have lead to the ability to actively manipulate surface atoms, study the surfaces of organic films, and to atomically examine surfaces under real catalytic conditions of elevated temperatures and pressures.