A theoretical study on chemical ordering of 38-atom trimetallic Pd-Ag-Pt nanoalloys
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Dosyalar
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
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Yayıncı
Iop Publishing Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, truncated octahedron (TO) structure is selected for further analysis and we focus on 38-atom Pd-Pt-Ag trimetallic nanoalloys. The best chemical ordering structures of Pd(n)Ag(32 -n)Pt(6)trimetallic nanoalloys are obtained at Gupta level. The structures with the lowest energy at Gupta level are then re-optimized by density functional theory (DFT) relaxations and DFT results confirm the Gupta level calculations with small shifts on bond lengths indicating TO structure is favorable for 38-atom of Pd(n)Ag(32 -n)Pt(6)trimetallic nanoalloys. The DFT excess energy analysis shows that Pd(8)Ag(24)Pt(6)composition has the lowest excess energy value in common with excess energy analysis at Gupta level. In Pd(8)Ag(24)Pt(6)composition, eight Pd atoms are central sites of 8 (111) hexagonal facets of TO, 24 Ag atoms locate on surface, and 6 Pt atoms locate at the core of the structure. It is also obtained that all of the compositions except Pd(18)Ag(14)Pt(6)and Pd(20)Ag(12)Pt(6)exhibit a octahedral Pt core. Besides, it is observed that there is a clear tendency for Ag atoms to segregate to the surface and also Pt atoms prefer to locate at core due to order parameter (R) variations.
Açıklama
Anahtar Kelimeler
nanoalloys, chemical ordering, optimization, density functional theory (DFT), Global Optimization, Structural Optimization, Molecular Adsorption, Transition-Metals, Clusters, Dft, Ni, Minima, Gold
Kaynak
Chinese Physics B
WoS Q Değeri
Q3
Scopus Q Değeri
Q3
Cilt
29
Sayı
7
