- Title
- Surface-sandwich segregation phenomena in bimetallic Ag-Ni and Pd-Ni nanoparticles: a molecular dynamics study
- Creator
- Levchenko, E. V.; Evteev, A. V.; Belova, I. V.; Murch, G. E.
- Relation
- Defect and Diffusion Forum Vol. 289-292, p. 657-664
- Publisher Link
- http://dx.doi.org/10.4028/www.scientific.net/DDF.289-292.657
- Publisher
- Trans Tech Publications
- Resource Type
- journal article
- Date
- 2009
- Description
- By molecular dynamics simulation it is shown that interdiffusion in the initial f.c.c. Agcore (≈ 28 at. %) – Ni-shell (≈ 72 at. %) and Ni-core (≈ 34 at. %) – Pd-shell (≈ 66 at. %) nanoparticles can lead to surface–sandwich segregation. It is observed that there is a separation of the initial Ag-Ni core-shell structure into Ag-core – Ni-intermediate shell – Ag-disperse surface monolayer. The initial crystal Ni-Pd core-shell structure transforms to the core of a non-crystalline Pd-rich solid solution with quite strongly developed icosahedral short-range order, which is covered by a surface–sandwich shell, where Ni atoms are located in the centres of interpenetrating icosahedra of a subsurface Kagomé net layer while the Pd atoms occupy the vertices of the icosahedra and cover this Ni layer from inside and outside. We demonstrate that under certain conditions a surface–sandwich segregation phenomenon at the nanoscale can be observed in systems with completely different phase diagrams in the bulk states: in systems displaying the extremely low mutual solubility as in the Ag-Ni system, or in systems exhibiting a continuous mutual solid solubility like the Pd-Ni system.
- Subject
- molecular dynamics; embedded atom method; interdiffusion; surface segregation; silver; palladium; nickel; alloy nanoparticles
- Identifier
- http://hdl.handle.net/1959.13/809086
- Identifier
- uon:7831
- Identifier
- ISSN:1012-0386
- Language
- eng
- Full Text
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