Exotic Behavior of the Outer Shell of Bimetallic Nanoalloys

被引：40

作者：

Delfour, L. ^{[1
,2
]}

Creuze, J. ^{[1
]}

Legrand, B. ^{[2
]}

机构：

[1] Univ Paris 11, LEMHE ICMMO, F-91405 Orsay, France

[2] CEA Saclay, DMN, SRMP, F-91191 Gif Sur Yvette, France

来源：

PHYSICAL REVIEW LETTERS | 2009年 / 103卷 / 20期

关键词：

NANOPARTICLES; TRANSITION; CLUSTERS;

D O I：

10.1103/PhysRevLett.103.205701

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

In order to build the phase diagram of Cu-Ag nanoalloys, segregation isotherms for the different sites of the outer shell of a 405-atom cluster have been obtained by means of Monte Carlo simulations using N-body interatomic potentials. A dynamical equilibrium in phase space is observed for the (001) facets as well as for the (111) facets of the truncated octahedron. For the (001) facets, the bistability originates from a structural transition, the facets oscillating collectively between a Cu-rich square shape of coordinence 4 and an Ag-rich diamond shape of coordinence 6. For the (111) facets, the bistability is purely chemical and affects each facet individually. We thus predict the possible coexistence of Cu-pure and Ag-pure (111) facets within the same nanoparticle.

引用

页数：4

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