Dresden 2006 – wissenschaftliches Programm

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MM: Metall- und Materialphysik

MM 29: Poster Session (SYNW)

MM 29.3: Poster

Donnerstag, 30. März 2006, 10:00–11:00, P4

Reaction pathways of a regular disintegration of nanowires by thermocapillarity — •Lars Röntzsch and Karl-Heinz Heinig — Foschungszentrum Rossendorf, Dresden

Surface free energy minimization leads to morphological changes of wires, e.g. disintegration into a droplet chains (Rayleigh instability). At the nano-scale, capillary effects are much more pronounced than in macroscopic systems due to the large surface-to-volume ratio. However, capillary-driven self-organization processes are subject to increasing fluctuations with decreasing dimensions, which mostly prevent the formation of regular structures with long-range order. In this contribution, we predict by means of kinetic Monte Carlo simulations a novel method to fabricate size-controlled chains of nanodroplets. Our prediction rests on the temperature dependence of surface tension - the origin of thermocapillarity. Uncompensated forces occur due to surface temperature gradients. A surface tension gradient triggers the biased migration of atoms from hot to cold regions by surface diffusion. A periodic temperature gradient along a nanowire might be achieved by a surface-plasmon-polariton wave. Thus, long-range regularity of nanodroplet chains, that form during a self-organized disintegration of nanowires, might be considerably improved.