Surface order-disorder phase transitions and percolation

M. C. GIMÉNEZ; F. NIETO; A. J. RAMIREZ-PASTOR

JOURNAL OF CHEMICAL PHYSICS

American Institute of Physics

Lugar: EE.UU.; Año: 2006 p. 1847071 - 1847077

0021-9606

In the present paper, the connection between surface order-disorder phase transitions and thepercolating properties of the adsorbed phase has been studied. For this purpose, four lattice-gasmodels in the presence of repulsive interactions have been considered. Namely, monomers onhoneycomb, square, and triangular lattices, and dimers (particles occupying two adjacent adsorptionsites) on square substrates. By using Monte Carlo simulation and finite-size scaling analysis, weobtain the percolation threshold theta_c of the adlayer, which presents an interesting dependence with w/k_BT  (w,k_B, and T being the lateral interaction energy, the Boltzmann constant, and thetemperature, respectively). For each geometry and adsorbate size, a phase diagram separating apercolating and a nonpercolating region is determined.