Electronic-Statistical Theories of the Multilayer Surface Segregation Effect in Binary Substitution Alloys (Review)

摘要

The review of the electronic theories of surface segregation in binary alloys of 8imple and transition metals is presented. The theories representing the semi-infinite alloy as a jelly within the scope of the pseudopotential model or within framework of tight-binding approximation are considered. Particular attention is given to the tight-binding approach used in a great number of papers prediction of the surface segregation in extremely diluted alloys of 3d-, and 4d-transition metals. References devoted to a more detailed study of depth-concentration profiles and composition polytherms for the near-region of systems Pt-Ni, Cu-Ni, Pt-Rh, Ag-Ni and Cu-Ag have analysed. Theoretical results obtained within the framework of the electronic and quasi-chemical theories of surface segregation are compared with other and with available experimental data.