Shockley-type surface states on low-index faces of Cu-based alloys with polyvalent solutes
R Prasad; A Y Serageldin; A Bansil; R Prasad; Dept. of Phys., Northeastern Univ., Boston, MA, USA; A Y Serageldin; Dept. of Phys., Northeastern Univ., Boston, MA, USA; A Bansil; Dept. of Phys., Northeastern Univ., Boston, MA, USA
Журнал:
Journal of Physics: Condensed Matter
Дата:
1991-02-18
Аннотация:
The authors consider Shockley-type surface states (SSS) in substitutionally disordered alloys. For this purpose the Green function for the semi-infinite system is obtained by matching the bulk Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) Green function with the free-electron Green function on the bounding surface.The formalism is applied to calculate binding energies and disorder induced smearings of the Y-centred SSS on the (110) surface and the Gamma -centred SSS on the (111) surfaces of Cu, Cu<sub>90</sub>Al<sub>10</sub>, Cu<sub>70</sub>Zn<sub>30</sub>, and Cu<sub>90</sub>Ge<sub>10</sub>. Their theoretical predictions with regard to changes in the binding energy and the disorder induced smearing in Cu<sub>90</sub>Al<sub>10</sub> where corresponding angle-resolved photoemission experiments are available for comparison are in reasonable accord with measurements. Their computations indicate that the binding energy of the SSS in Cu-based alloys will generally increase with increasing electron/atom (e/a) ratio.
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