Copper-palladium alloy surfaces: II. Equilibrium surface compositions of dilute Pd/Cu alloys from a simple segregation model

• Published in: Surface science 1991-12, Vol.259 (1), p.56-64
• Main Authors: Newton, M.A., Francis, S.M., Bowker, M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Metals. Metallurgy; Physics; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(91)90523-U

The composition of the CuPd[85:15](110) alloy selvedge region has been modelled using a quasichemical bond breaking model of surface segregation. The results of these calculations have been compared to those obtained from experimental studies of this surface, and it is shown that despite the neglect of size mismatch of solute and solvent atoms and the formal neglect of the ordering of the selvedge, the results are in agreement with experimental observations of an all Cu top layer, and a second layer significantly enriched in Pd. The results for the top layer Pd concentration are compared to those made by a more comprehensive but general theory of segregation. Comparisons to the analogous Cu 3Au alloy surfaces and the Pt in Cu case are made, as are predictions about equilibrium selvedge compositions of other dilute Pd in Cu alloys.