Two Approaches to Dislocation Nucleation in the Supported Heteroepitaxial Equilibrium Islanding Phenomenon

TL;DR

This paper compares Molecular Static and Phase Field Crystal methods to analyze dislocation nucleation in 2D nanoscopic islands, revealing consistent qualitative stages and energy behaviors during the process.

Contribution

It introduces two computational approaches to study dislocation nucleation in heteroepitaxial islands, demonstrating their qualitative agreement and providing insights into nucleation stages.

Findings

Both methods show the same qualitative nucleation stages.

Dislocations nucleate at the film-substrate contact point.

Energy decreases monotonically as dislocations move away from contact points.

Abstract

We study the dislocation formation in 2D nanoscopic islands with two methods, the Molecular Static method and the Phase Field Crystal method. It is found that both methods indicate the same qualitative stages of the nucleation process. The dislocations nucleate at the film-substrate contact point and the energy decreases monotonously when the dislocations are farther away from the island-wetting film contact points than the distance of the highest energy barrier.