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Published on: February 15, 2016
Growth anomalies in supramolecular networks: 4,4'-biphenyldicarboxylic acid on cu(001)
Daniel Schwarz1, Raoul van Gastel1, Harold J W Zandvliet1
1Physics of Interfaces and Nanomaterials, MESA^{+} Institute for Nanotechnology, University of Twente, P. O. Box 217, NL-7500 AE Enschede, The Netherlands.
Abstract:
We have used low energy electron microscopy to demonstrate how the interaction of 4,4'-biphenyldicarboxylic acid (BDA) molecules with (steps on) the Cu(001) surface determines the structure of supramolecular BDA networks on a mesoscopic length scale. Our in situ real time observations reveal that steps are permeable to individual molecules but that the change in crystal registry between different layers of the Cu substrate causes them to be completely impermeable to condensed BDA domains. The resulting growth instabilities determine the evolution of the domain shape and include a novel Mullins-Sekerka-type growth instability that is characterized by high growth rates along, instead of perpendicular to, the Cu steps. This growth instability is responsible for the majority of residual defects in the BDA networks.
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