ABSTRACT
The surface we conceive is an interface with air or vacuum. In this sense, the term ‘‘surface’’ is a mispresentation of the interface of a material with air or in some cases with vacuum; i.e., in the cases of surface analysis in vacuum such X-ray photoemission spectroscopy (XPS), secondary ion mass spectroscopy (SIM), and so forth. Only when the contacting medium is other than air or vacuum does the term interface come into our conception. Thus, if the contacting medium is a gas phase, the term interface is not generally used, and the interface is more or less limited to the boundary between two matters in condensed phase, i.e., liquid/liquid, liquid/solid and solid/solid. However, according to the broader meaning of a boundary between two different matters, every surface we conceive is an interface with a contacting medium. Therefore, ‘‘surface’’ cannot be fully described without identifying the contacting medium. The change of surface properties, often dealt as surface dynamics, could stem, at least in part, to the mishandling of interfaces.
