Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation
Gold–copper (Au–Cu) phases were employed already by pre-Columbian civilizations, essentially in decorative arts, whereas nowadays, they emerge in nanotechnology as an important catalyst. The knowledge of the phase diagram is critical to understanding the performance of a material. However, experimen...
| Autores principales: | , , , , , |
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| Formato: | Artículo |
| Lenguaje: | inglés |
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American Chemical Society
2014
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| Materias: | |
| Acceso en línea: | http://eprints.uanl.mx/8907/1/Gold%E2%88%92Copper%20Nano-Alloy%2C%20Tumbaga%2C%20in%20the%20Era%20of%20Nano%20Phase%20Diagram%20and%20Segregation.pdf |
| _version_ | 1824370863060811776 |
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| author | Guisbiers, Grégory Mejía Rosales, Sergio Khanal, Subarna Ruiz Zepeda, Francisco Whetten, Robert L. Yacamán, Miguel José |
| author_facet | Guisbiers, Grégory Mejía Rosales, Sergio Khanal, Subarna Ruiz Zepeda, Francisco Whetten, Robert L. Yacamán, Miguel José |
| author_sort | Guisbiers, Grégory |
| collection | Repositorio Institucional |
| description | Gold–copper (Au–Cu) phases were employed already by pre-Columbian civilizations, essentially in decorative arts, whereas nowadays, they emerge in nanotechnology as an important catalyst. The knowledge of the phase diagram is critical to understanding the performance of a material. However, experimental determination of nanophase diagrams is rare because calorimetry remains quite challenging at the nanoscale; theoretical investigations, therefore, are welcomed. Using nanothermodynamics, this paper presents the phase diagrams of various polyhedral nanoparticles (tetrahedron, cube, octahedron, decahedron, dodecahedron, rhombic dodecahedron, truncated octahedron, cuboctahedron, and icosahedron) at sizes 4 and 10 nm. One finds, for all the shapes investigated, that the congruent melting point of these nanoparticles is shifted with respect to both size and composition (copper enrichment). Segregation reveals a gold enrichment at the surface, leading to a kind of core–shell structure, reminiscent of the historical artifacts. Finally, the most stable structures were determined to be the dodecahedron, truncated octahedron, and icosahedron with a Cu-rich core/Au-rich surface. The results of the thermodynamic approach are compared and supported by molecular-dynamics simulations and by electron-microscopy (EDX) observations. |
| format | Article |
| id | eprints-8907 |
| institution | UANL |
| language | English |
| publishDate | 2014 |
| publisher | American Chemical Society |
| record_format | eprints |
| spelling | eprints-89072016-02-17T17:29:46Z http://eprints.uanl.mx/8907/ Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation Guisbiers, Grégory Mejía Rosales, Sergio Khanal, Subarna Ruiz Zepeda, Francisco Whetten, Robert L. Yacamán, Miguel José Q Ciencias en General QC Física Gold–copper (Au–Cu) phases were employed already by pre-Columbian civilizations, essentially in decorative arts, whereas nowadays, they emerge in nanotechnology as an important catalyst. The knowledge of the phase diagram is critical to understanding the performance of a material. However, experimental determination of nanophase diagrams is rare because calorimetry remains quite challenging at the nanoscale; theoretical investigations, therefore, are welcomed. Using nanothermodynamics, this paper presents the phase diagrams of various polyhedral nanoparticles (tetrahedron, cube, octahedron, decahedron, dodecahedron, rhombic dodecahedron, truncated octahedron, cuboctahedron, and icosahedron) at sizes 4 and 10 nm. One finds, for all the shapes investigated, that the congruent melting point of these nanoparticles is shifted with respect to both size and composition (copper enrichment). Segregation reveals a gold enrichment at the surface, leading to a kind of core–shell structure, reminiscent of the historical artifacts. Finally, the most stable structures were determined to be the dodecahedron, truncated octahedron, and icosahedron with a Cu-rich core/Au-rich surface. The results of the thermodynamic approach are compared and supported by molecular-dynamics simulations and by electron-microscopy (EDX) observations. American Chemical Society 2014 Article PeerReviewed text en cc_by_nc_nd http://eprints.uanl.mx/8907/1/Gold%E2%88%92Copper%20Nano-Alloy%2C%20Tumbaga%2C%20in%20the%20Era%20of%20Nano%20Phase%20Diagram%20and%20Segregation.pdf http://eprints.uanl.mx/8907/1.haspreviewThumbnailVersion/Gold%E2%88%92Copper%20Nano-Alloy%2C%20Tumbaga%2C%20in%20the%20Era%20of%20Nano%20Phase%20Diagram%20and%20Segregation.pdf Guisbiers, Grégory y Mejía Rosales, Sergio y Khanal, Subarna y Ruiz Zepeda, Francisco y Whetten, Robert L. y Yacamán, Miguel José (2014) Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation. Nano Letters, 14 (11). pp. 6718-6726. ISSN 1530-6984 |
| spellingShingle | Q Ciencias en General QC Física Guisbiers, Grégory Mejía Rosales, Sergio Khanal, Subarna Ruiz Zepeda, Francisco Whetten, Robert L. Yacamán, Miguel José Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation |
| thumbnail | https://rediab.uanl.mx/themes/sandal5/images/online.png |
| title | Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation |
| title_full | Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation |
| title_fullStr | Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation |
| title_full_unstemmed | Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation |
| title_short | Gold−Copper Nano-Alloy, “Tumbaga”, in the era of nano: phase diagram and segregation |
| title_sort | gold copper nano alloy tumbaga in the era of nano phase diagram and segregation |
| topic | Q Ciencias en General QC Física |
| url | http://eprints.uanl.mx/8907/1/Gold%E2%88%92Copper%20Nano-Alloy%2C%20Tumbaga%2C%20in%20the%20Era%20of%20Nano%20Phase%20Diagram%20and%20Segregation.pdf |
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