Study of the island morphology at the early stages of Fe/Mo(110) MBE growth

TL;DR

This study uses atomistic simulations to analyze how Fe island shapes evolve on Mo(110) surfaces during early MBE growth, revealing temperature-dependent morphological transitions from fractal to faceted to rounded shapes.

Contribution

It introduces a detailed atomistic SOS model with bond counting for Fe/Mo(110) growth, providing new insights into temperature-driven morphological changes.

Findings

At low temperatures, islands are fat fractals.

At 500K, islands become faceted rhombic shapes.

At higher temperatures, islands are rounded.

Abstract

We present theoretical study of morphology of Fe islands grown at Mo(110) surface in sub-monolayer MBE mode. We utilize atomistic SOS model with bond counting, and interactions of Fe adatom up to third nearest neighbors. We performed KMC simulations for different values of adatom interactions and varying temperatures. We have found that, while for the low temperature islands are fat fractals, for the temperature 500K islands have faceted rhombic-like shape. For the higher temperature, islands acquire a rounded shape. In order to evaluated qualitatively morphological changes, we measured averaged aspect ration of islands. We calculated dependence of the average aspect ratio on the temperature, and on the strength of interactions of an adatom with neighbors.