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arXiv · 1009.6037

Real-Time Imaging of K atoms on Graphite: Interactions and Diffusion

J. Renard·M. B. Lundeberg·J. A. Folk·Y. Pennec
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Abstract

Scanning tunneling microscopy (STM) at liquid helium temperature is used to image potassium adsorbed on graphite at low coverage (~0.02 monolayer). Single atoms appear as protrusions on STM topographs. A statistical analysis of the position of the atoms demonstrates repulsion between adsorbates, which is quantified by comparison with molecular dynamics simulations. This gives access to the dipole moment of a single adsorbate, found to be 10.5 Debye. Time lapse imaging shows that long range order is broken by thermally activated diffusion, with a 32 meV barrier to hopping between graphite lattice sites.

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J. Renard, M. B. Lundeberg, J. A. Folk, Y. Pennec. 2010-09-30. Real-Time Imaging of K atoms on Graphite: Interactions and Diffusion. https://doi.org/10.1103/physrevlett.106.156101

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