O 2 induced Cu surface segregation in Au-Cu alloys studied by angle resolved XPS and DFT modelling
Surface segregation effects on polycrystalline Au-Cu alloys (Au 0.80Cu 0.20, Au 0.85Cu 0.15 and Au 0.90Cu 0.10) were studied at room temperature by angle resolved XPS (ARXPS) and density functional theory (DFT) before and after exposure to O 2. Au surface enrichment was found as predicted from calcu...
| Autores principales: | , , |
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| Publicado: |
2012
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14639076_v14_n20_p7448_Volker http://hdl.handle.net/20.500.12110/paper_14639076_v14_n20_p7448_Volker |
| Aporte de: |
| Sumario: | Surface segregation effects on polycrystalline Au-Cu alloys (Au 0.80Cu 0.20, Au 0.85Cu 0.15 and Au 0.90Cu 0.10) were studied at room temperature by angle resolved XPS (ARXPS) and density functional theory (DFT) before and after exposure to O 2. Au surface enrichment was found as predicted from calculations showing that this process is energetically favourable, with a segregation energy for Au in a Cu matrix of -0.37 eV atom -1. Surface enrichment with Cu was observed after exposure to O 2 due to its dissociative adsorption, in agreement with DFT calculations that predicted an energy gain of -1.80 eV atom -1 for the transfer of Cu atoms to a surface containing adsorbed oxygen atoms, thus leading to an inversion in surface population. © 2012 the Owner Societies. |
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