Solid-state amorphization of Cu nanolayers embedded in a Cu64Zr36 glass

TL;DR

This study uses molecular dynamics simulations to explore how crystalline copper nanolayers embedded in a metallic glass become amorphous, revealing the role of interface energy and layer orientation in this transformation.

Contribution

It introduces a thermodynamic model explaining solid-state amorphization driven by interface energy reduction, specific to different nanolayer orientations.

Findings

Amorphization occurs when interface energy reduction outweighs bulk energy costs.

The critical layer thickness for amorphization depends on orientation.

The structure of amorphous layers resembles quenched copper melt.

Abstract

Solid-state amorphization of crystalline copper nanolayers embedded in a Cu64Zr36 metallic glass is studied by molecular dynamics simulations for different orientations of the crystalline layer. We show that solid-state amorphization is driven by a reduction of interface energy, which compensates the bulk excess energy of the amorphous nanolayer with respect to the crystalline phase up to a critical layer thickness. A simple thermodynamic model is derived, which describes the simulation results in terms of orientation-dependent interface energies. Detailed analysis reveals the structure of the amorphous nanolayer and allows a comparison to a quenched copper melt, providing further insights into the origin of excess and interface energy.