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Article
Communication: Diverse nanoscale cluster dynamics: Diffusion of 2D epitaxial clusters
Ames Laboratory Accepted Manuscripts
  • King C. Lai, Iowa State University and Ames Laboratory
  • James W. Evans, Iowa State University and Ames Laboratory
  • Da-Jiang Liu, Ames Laboratory
Publication Date
11-29-2017
Department
Ames Laboratory; Physics and Astronomy
OSTI ID+
1411951
Report Number
IS-J 9460
DOI
10.1063/1.5008424
Journal Title
Journal of Chemical Physics
Abstract
The dynamics of nanoscale clusters can be distinct from macroscale behavior described by continuum formalisms. For diffusion of 2D clusters of N atoms in homoepitaxial systems mediated by edge atom hopping, macroscale theory predicts simple monotonic size scaling of the diffusion coefficient, DN ∼ N−β, with β = 3/2. However, modeling for nanoclusters on metal(100) surfaces reveals that slow nucleation-mediated diffusion displaying weak size scaling β < 1 occurs for “perfect” sizes Np = L2 and L(L+1) for integer L = 3,4,… (with unique square or near-square ground state shapes), and also for Np+3, Np+4,…. In contrast, fast facile nucleation-free diffusion displaying strong size scaling β ≈ 2.5 occurs for sizes Np+1 and Np+2. DN versus N oscillates strongly between the slowest branch (for Np+3) and the fastest branch (for Np+1). All branches merge for N = O(102), but macroscale behavior is only achieved for much larger N = O(103). This analysis reveals the unprecedented diversity of behavior on the nanoscale.
Language
en
Publisher
Iowa State University Digital Repository, Ames IA (United States)
Citation Information
King C. Lai, James W. Evans and Da-Jiang Liu. "Communication: Diverse nanoscale cluster dynamics: Diffusion of 2D epitaxial clusters" Vol. 147 Iss. 20 (2017) p. 201101
Available at: http://works.bepress.com/james-evans/178/