Growth of Three-Shell Onionlike Bimetallic Nanoparticles

Abstract

We show by molecular dynamics simulations on three systems ($B/A=\mathrm{P}\mathrm{d}/\mathrm{A}\mathrm{g}$, $\mathrm{C}\mathrm{u}/\mathrm{A}\mathrm{g}$, and $\mathrm{N}\mathrm{i}/\mathrm{A}\mathrm{g}$) that three-shell metallic nanoparticles made by a core of a metal $A$, an intermediate shell of metal $B$ and an external shell of metal $A$ ($A\mathrm{\text{\ensuremath{-}}}B\mathrm{\text{\ensuremath{-}}}A$ nanoparticles) can be grown by deposition of $B$ atoms onto an $A$ core. The growth of the intermediate $B$ shell is triggered by the fact that the most favorable positions for isolated $B$ impurities inside $A$ clusters are located just one layer below the cluster surface.