Solid-state dewetting instability in thermally-stable nanocrystalline binary alloys

TL;DR

This study investigates how alloy composition influences solid-state dewetting in thermally-stable nanocrystalline metallic thin films, revealing that doping levels can mitigate dewetting severity while maintaining stability.

Contribution

It provides new insights into controlling dewetting behavior through alloy composition tuning in thermally-stable nanocrystalline thin films.

Findings

Dewetting severity decreases with more dilute alloy compositions.

Both studied alloys exhibit dewetting after annealing.

Dopant concentration tuning balances stability and dewetting risk.

Abstract

Practical applications of nanocrystalline metallic thin films are often limited by instabilities. In addition to grain growth, the thin film itself can become unstable and collapse into islands through solid-state dewetting. Selective alloying can improve nanocrystalline stability, but the impact of this approach on dewetting is not clear. In this study, two alloys that exhibit nanocrystalline thermal stability as ball milled powders are evaluated as thin films. While both alloys demonstrated dewetting behavior following annealing, the severity decreased in more dilute compositions. Ultimately, a balance may be struck between nanocrystalline stability and thin film structural stability by tuning dopant concentration.