The Structural Behavior of Physisorbed Metallenes

TL;DR

This study investigates the structural properties of atomically thin physisorbed metallenes, revealing how their buckling can be controlled via stress and electric fields, aiding in their stabilization and application.

Contribution

It provides a detailed multi-scale analysis of physisorbed metallenes, showing how external stimuli can manipulate their structure, which was not previously well understood.

Findings

Most metallenes are buckled but can be flattened by stress.

Electric fields can increase the adhesion threshold for flattening.

Structural control is possible through substrate choice and external parameters.

Abstract

Atomically thin metallenes have properties attractive for applications, but they are intrinsically unstable and require delicate stabilization in pores or other nano-constrictions. Substrates provide solid support, but metallenes' wanted properties can only be retained in weak physisorption. Here, we study the 45 physisorbed, atomically thin metallene structures in flat and buckled lattices using a sequential multi-scale model based on density-functional theory calculations. The lattices are mostly buckled but flat for a handful of elements such as Na, K, Rb, Ag, Au, and Cd, depending on physisorption strength. Moreover, under certain conditions, the structure can be controlled by applying biaxial tensile stress parallel or an electric field normal to the surface. The stress reduces the threshold of adhesion strength required to flatten a buckled lattice, and the electric field can be used to increase that threshold controllably. Our results help provide fundamental information about the structures of physisorbed metallenes and suggest means to control them at will by suitable substrate choice or tuning of experimental parameters.