In the course of heating of metals, impurities in metals often segregated to surfaces or grain-boundaries, and the compositions of surfaces or interfaces are different from that of the bulk. The properties of materials are strongly affected by these segregation behaviors.
Although much research on the segregation behaviors of metals have been published already, surface thermodynamics has not been established yet. This review discusses free energy diagrams of surfaces and the segregation isotherms, largely from the point of view of Gibbs' dividing surface model and indicates how the interaction between segregants will affect the segregation behaviors on metal surfaces. Throughout this review, attempts are made to understand the basic concepts of surface thermodynamics of metals.
