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Surface composition of clean and oxidized Pd75Ag25(100) from photoelectron spectroscopy and density functional theory calculations

Författare:
Publiceringsår: 2012
Språk: Engelska
Sidor: 1777-1782
Publikation/Tidskrift/Serie: Surface Science
Volym: 606
Nummer: 23-24
Dokumenttyp: Artikel
Förlag: Elsevier

Sammanfattning

High resolution photoelectron spectroscopy and density functional theory calculations have been used to study the composition of clean and oxidized Pd75Ag25( 100). The results for the clean surface confirm earlier reports of surface segregation by Wouda et al. (1998), where the top most layers are rich in Ag. The Pd 3d core level component from the surface region is observed at higher binding energies than the contribution from the bulk which is found to be a signature of Pd embedded in Ag. Low energy electron diffraction and scanning tunneling microscopy measurements reveal that oxidation of the Pd75Ag25(100) surface results in a (root 5 x root 5)R27 degrees-O structure similar to the one reported for Pd(100). The calculations suggest that the stable structure is a PdO(101) monolayer supported on a (100) surface rich in Ag at the interface to the stoichiometric alloy. The calculated core level shifts for the oxidized surface are in good agreement with the experimental observations. (C) 2012 Elsevier B.V. All rights reserved.

Disputation

Nyckelord

  • Physics and Astronomy
  • PdAg alloy
  • Surface oxide
  • Core level shifts
  • Pd75Ag25(100)
  • Photoelectron spectroscopy
  • Density functional theory

Övriga

Published
Yes
  • ISSN: 0039-6028

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