APPLICATION OF AN IMPROVED THERMODYNAMIC DESCRIPTION OF MULTILAYER SURFACE COMPOSITIONS OF BINARY-ALLOYS

The previous developed new thermodynamic theory, the ''modern thermodynamic calculation of interface properties'' (MTCIP), in its first calculational approximation to a successful description of the surface composition of dilute binary alloys, has been improved in a multilayer description (using several surface atomic sublayers) by allowing for any bulk composition, accounting for farther than first neighbour effects, describing component partial molar surface areas as functions of the mixture surface composition, and including a treatment of surface reconstructions. The calculations for the {100}, {110} and {111} surfaces of Pt50Ni50 single crystal alloys at approximate to 1000 K are presented, which are in good agreement with experimental results [1-3] for all surface atomic sublayers and all surface orientations.