Kinetics of chemical ordering in a Ag-Pt nanoalloy particle via first-principles simulations
- CNR-IPCF, Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche, Molecular Modeling Laboratory, via G. Moruzzi 1, Pisa I56124 (Italy)
- Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of)
- Department of Chemistry and Nanotechnology Center, Sharif University of Technology, Tehran (Iran, Islamic Republic of)
- Los Alamos National Laboratories, Division of Materials Science and Technology, Los Alamos, New Mexico 87545 (United States)
The energetics and kinetic energy barriers of vacancy/atom exchange in a 37-atom truncated octahedron Ag-Pt binary cluster in the Ag-rich range of compositions are investigated via a first-principles atomistic approach. The energy of the local minima obtained considering various distributions of a single vacancy and a few Pt atoms within the cluster and the energy barriers connecting them are evaluated using accurate density-functional calculations. The effects of the simultaneous presence of a vacancy and Pt atoms are found to be simply additive when their distances are larger than first-neighbors, whereas when they can be stabilizing at low Pt content due to the release of strain by the Pt/vacancy interaction or destabilizing close to a perfect Pt(core)/Ag(shell) arrangement. It is found that alloying with Pt appreciably increases the barriers for homotops transformations, thus rationalizing the issues encountered at the experimental level in producing Ag-Pt equilibrated nanoparticles and bulk phase diagram.
- OSTI ID:
- 22100660
- Journal Information:
- Journal of Chemical Physics, Vol. 137, Issue 19; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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