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: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/70957 |
| Acceso en línea: | http://hdl.handle.net/11336/70957 |
| Access Level: | acceso abierto |
| Palabra clave: | Alloys Au Cu Xps https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| 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. |
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