Structural modification of Au-Co thin films induced by annealing in oxidizing atmosphere
| Autor: | Boris Kalinic, Giovanni Mattei, Ionut Gabriel Balasa, Valentina Mattarello, Niccolò Michieli, Chiara Maurizio, Carlo Scian |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Grazing incidence X-ray diffraction Absorption spectroscopy Annealing (metallurgy) Alloy Metastable bimetallic alloy 02 engineering and technology engineering.material 010402 general chemistry 01 natural sciences Oxidizing agent Materials Chemistry Thin film X-ray nanoimaging Materials for magnetoplasmonics Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films Physical vapor deposition Chemical engineering Nanocrystal engineering 0210 nano-technology Solid solution |
| Popis: | The stability upon air-annealing of uncapped Au-Co thin films is investigated. The analysis focuses on the modifications of the crystalline fraction of the films produced by physical vapor deposition. The film with the highest Au concentration exhibits the strongest diffraction signal, corresponding to a Au-rich fcc AuxCo1−x solid solution alloy, with nanocrystals which have a rod-like shape. Air annealing induces a progressive de-alloying which is complete at 500 °C, as shown by X-ray Absorption Spectroscopy and X-ray diffraction. The film, that is directly exposed to the oxidizing atmosphere, undergoes a de-wetting process, likely triggered by Au. X-ray nanoimaging mapping enlightens the presence of interpenetrating sub-μm Au and Co3O4 domains. This peculiar annealed nanostructured system can have interesting applications in the field of catalysis. |
| Databáze: | OpenAIRE |
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