Coherency Strain-Assisted Equilibrium Segregation at Heterophase Interfaces

Theoretical work in the field of interfacial segregation is focused mainly on the sharp interface approach beginning with the Gibbs’ introduction of the dividing surface. In this paper a continuum approach to the problem of interfacial segregation, which deals with continuous distributions of quantities at interfaces, is developed. The current study concentrates on heterophase interfaces in alloys as opposed to grain boundaries or antiphase domain boundaries. The important effect of coherency strains is taken into account. The Gibbs adsorption theorem is discussed in the framework of a continuum approach. A comparison is made between the sharp (Gibbsian) and diffuse interface approaches.