Dynamical stability of two-dimensional metals in the periodic table

TL;DR

This paper investigates the dynamical stability of various two-dimensional elemental metals using first-principles phonon calculations, revealing relationships with 3D stability and implications for alloy design.

Contribution

It introduces a systematic first-principles approach to assess 2D metal stability and links it to 3D structures, aiding in the design of stable 2D alloys.

Findings

Phonon band structures identify stable 2D metals from Li to Pb.

Stability correlates with 3D structural stability.

Material design insights for stable 2D alloys.

Abstract

We study the dynamical stability of elemental two-dimensional (2D) metals from Li to Pb by calculating the phonon band structure from first principles, where 2D structures are assumed to be planer hexagonal, buckled honeycomb, and buckled square lattice structures. We show the relationship between the stability of 2D structures and that of three-dimensional structures. This provides a material design concept for alloys, where the similarity with regard to the stable 2D structures, rather than the energetic stability of alloy, is important to yield dynamically stable alloys.