Free-standing 2D metals from binary metal alloys

TL;DR

This study uses simulations to explore the formation of free-standing monolayers from binary metal alloys, inspired by recent experimental findings with Au-Ag alloys, and suggests potential for creating various 2D metal monolayers.

Contribution

It introduces a semi-empirical simulation approach to predict monolayer formation in multiple binary metal alloys, extending experimental insights to new material combinations.

Findings

Dealloying energy for Ag in Au-Ag alloys is lower than Au monolayer breakage energy.

Simulations indicate potential to form Au monolayers from Au-Cu alloys.

Potential to create Pt monolayers from Pt-Cu, Pt-Ni, and Pt-Pd alloys.

Abstract

Recent experiment demonstrated the formation of free-standing Au monolayers by exposing Au-Ag alloy to electron beam irradiation. Inspired by this discovery, we used semi-empirical effective medium theory simulations to investigate monolayer formation in 30 different binary metal alloys composed of late d-series metals Ni, Cu, Pd, Ag, Pt, and Au. In qualitative agreement with the experiment, we find that the beam energy required to dealloy Ag atoms from Au-Ag alloy is smaller than the energy required to break the dealloyed Au monolayer. Our simulations suggest that similar method could also be used to form Au monolayers from Au-Cu alloy and Pt monolayers from Pt-Cu, Pt-Ni, and Pt-Pd alloys.