Reduction of surface coverage of finite systems due to geometrical steps
Abstract
The coverage of vicinal, stepped surfaces with molecules is simulated with the help of a two-dimensional Ising model including local distortions and an Ehrlich-Schwoebel barrier term at the steps. An effective two-spin model is capable to describe the main properties of this distorted Ising model. It is employed to analyze the behavior of the system close to the critical points. Within a well-defined regime of bonding strengths and Ehrlich-Schwoebel barriers we find a reduction of coverage (magnetization) at low temperatures due to the presence of the surface step. This results in a second, low-temperature transition besides the standard Ising order-disorder transition. The additional transition is characterized by a divergence of the susceptibility as a finite-size effect. Due to the surface step the mean-field specific heat diverges with a power law.
Keywords
Cite
@article{arxiv.cond-mat/0608013,
title = {Reduction of surface coverage of finite systems due to geometrical steps},
author = {K. Morawetz and C. Olbrich and S. Gemming and M. Schreiber},
journal= {arXiv preprint arXiv:cond-mat/0608013},
year = {2015}
}
Comments
corrected version 7 pages, 4 figures