Island diffusion on metal fcc(100) surfaces

TL;DR

This paper uses Monte Carlo simulations to study how adatom islands diffuse on Cu(100) surfaces, revealing a size-dependent scaling exponent that transitions from periphery to vacancy diffusion regimes, aligning with theoretical and experimental results.

Contribution

It introduces a detailed simulation analysis showing the crossover in diffusion mechanisms and the size dependence of the scaling exponent on Cu(100) surfaces.

Findings

Scaling exponent decreases with island size

Crossover from periphery to vacancy diffusion

Results agree with theory and experiments

Abstract

We present Monte Carlo simulations for the size and temperature dependence of the diffusion coefficient of adatom islands on the Cu(100) surface. We show that the scaling exponent for the size dependence is not a constant but a decreasing function of the island size and approaches unity for very large islands. This is due to a crossover from periphery dominated mass transport to a regime where vacancies diffuse inside the island. The effective scaling exponents are in good agreement with theory and experiments.