AVS 46th International Symposium
    Surface Science Division Friday Sessions
       Session SS2-FrM

Paper SS2-FrM1
Quantitative Determination of Adsorbate Interactions on an Iron Surface

Friday, October 29, 1999, 8:20 am, Room 607

Session: Adsorption on Metals and Silicon
Presenter: F. Besenbacher, University of Aarhus, Denmark
Authors: L. Österlund, University of Aarhus, Denmark
M.O. Pedersen, University of Aarhus, Denmark
I. Stensgaard, University of Aarhus, Denmark
E. Laegsgaard, University of Aarhus, Denmark
F. Besenbacher, University of Aarhus, Denmark
Correspondent: Click to Email
We introduce a new concept of Configuration Distribution Analysis (CDA) to extract quantitative values of the adsorbate-adsorbate interaction potential from Scanning Tunneling Microscopy (STM) data. By analyzing atomically resolved nitrogen islands on a Fe(100) surface, we show that the propensity of small, compact c(2x2) islands is due to a many-body effect in combination with elastic interactions. It is shown that the nearest and next-nearest neighbour interactions are strongly repulsive and weakly attractive, respectively, where the latter is modulated by the nearest neighbour coordination. Accurate determination of adsorbate-adsorbate interactions are essential to understand a variety of surface phenomena, and until now, there has been a lack of reliable experimental results. The results presented here promise to provide a new tool to bridge this gap.