Evolution of topological order in Xe films on a quasicrystal surface

TL;DR

This study uses grand canonical Monte Carlo simulations to explore how xenon films grow and change structure on a quasicrystalline surface, revealing temperature-dependent transitions in topological order.

Contribution

First simulation study of gas adsorption on a quasicrystal surface, demonstrating structural evolution and phase transitions consistent with experimental data.

Findings

Adsorption isotherms match LEED data.

Bulk film begins in second layer.

Order transitions depend on temperature.

Abstract

We report results of the first computer simulation studies of a physically adsorbed gas on a quasicrystalline surface, Xe on decagonal Al-Ni-Co. The grand canonical Monte Carlo method is employed, using a semi-empirical gas-surface interaction, based on conventional combining rules, and the usual Lennard-Jones Xe-Xe interaction. The resulting adsorption isotherms and calculated structures are consistent with the results of LEED experimental data. The evolution of the bulk film begins in the second layer, while the low coverage behavior is epitaxial. This transition from 5-fold to 6-fold ordering is temperature dependent, occurring earlier (at lower coverage) for the higher temperatures.