Two-dimensional roughening of adsorbate islands in thermodynamic equilibrium.
Equilibrium fluctuations of islands of adsorbed O atoms on Ru(0001) were investigated by scanning tunneling microscopy (STM), density functional theory calculations (DFT) and Monte Carlo (MC) simulations. Very ramified (2 x 2)-O islands were observed by high-speed STM that point to complex interactions between the O atoms. The DFT calculations show that, in addition to pairwise attractive interactions between third-nearest neighbors, a repulsive three-body interaction exists between these. MC simulations that include three-body interactions reproduce the observed ordering behavior.
Wintterlin
J
J
Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, and Ludwig-Maximilians-Universität, 80331 München, Germany.
Trost
J
J
Schuster
R
R
Eichler
A
A
McEwen
J-S
JS