Island Size Selectivity during 2D Ag Island Coarsening on Ag (111)

TL;DR

This study uses kinetic Monte Carlo simulations to analyze early-stage Ag island coarsening on Ag(111), revealing size selectivity driven by kinetic stability and barrier effects, independent of initial conditions.

Contribution

It introduces a detailed kinetic Monte Carlo model with environment-dependent barriers to explain island size selectivity during Ag coarsening.

Findings

Island size distribution shows peaks and valleys during coarsening.

Size selectivity is due to kinetically stable island sizes.

Selectivity is independent of initial island shapes and configurations.

Abstract

We report on early stages of submonolayer Ag island coarsening on Ag(111) surface at room temperature ($300$ K) carried out using realistic kinetic Monte Carlo (KMC) simulations. We find that during early stages, coarsening proceeds as a sequence of selected island sizes creating peaks and valleys in the island size distribution. We find that island-size selectivity is due to formation of kinetically stable islands for certain sizes because of adatom detachment/attachment processes and large activation barrier for kink detachment. In addition, we find that the ratio of number of adatom attachment to detachment processes to be independent of parameters of initial configuration and also on the initial shapes of the islands confirming that island-size selectivity is independent of initial conditions.These simulations were carried out using a very large database of processes identified by their local environment and whose activation barriers were calculated using the embedded-atom method.