Morphological instabilities of a thin film on a Penrose lattice: a Monte Carlo study

TL;DR

This study uses Monte Carlo simulations to analyze how a polycrystalline thin film relaxes on a Penrose lattice, revealing the influence of substrate defects on island formation and film morphology.

Contribution

Introduces a novel Monte Carlo approach to investigate the effects of substrate geometry and defects on thin film morphological instabilities.

Findings

Domains tend to align their orientation after relaxation.

Small islands form preferentially on central heptagon sites.

The substrate's Penrose lattice influences island distribution.

Abstract

We computed by a Monte Carlo method the thermal relaxation of a polycrystalline thin film deposited on a Penrose lattice. The thin film was modelled by a 2 dimensional array of elementary domains, which have each a given height. During the Monte Carlo process, the height of each of these elementary domains is allowed to change as well as their crystallographic orientation. After equilibrium is reached at a given numerical temperature, all elementary domains have changed their orientation into the same one and small islands appear, preferentially on the domains of the Penrose lattice located in the center of heptagons. This method is a new numerical approach to study the influence of the substrate and its defects on the islanding process of polycrystalline films.