Rapid diffusion of magic-size islands by combined glide and vacancy mechanism.
Using molecular dynamics, nudged elastic band, and embedded atom methods, we show that certain 2D Ag islands undergo extremely rapid one-dimensional diffusion on Cu(001) surfaces. Indeed, below 300 K, hopping rates for "magic-size" islands are orders of magnitude faster than hopping rates for single Ag adatoms. This rapid diffusion requires both the c(10 x 2) hexagonally packed superstructure typical of Ag on Cu(001) and appropriate "magic sizes" for the islands. The novel highly cooperative diffusion mechanism presented here couples vacancy diffusion with simultaneous core glide.
Uche
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Sandia National Laboratories, Livermore, California 94550, USA.
Perez
D
D
Voter
A F
AF
Hamilton
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JC