The process that differentiates the composition at an interface or surface from the average or bulk composition.
Note:
The composition of the segregated phases need not be uniform, for example, when concentration gradients are established in the phases.
Source:
PAC, 1994, 66, 577. 'Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)' on page 590 (https://doi.org/10.1351/pac199466030577)