The structural behavior of physisorbed metallenes

TL;DR

This paper explores how the structure of ultra-thin metallenes can be controlled using weak interactions with substrates.

Contribution

The study introduces a method to control metallene structures using physisorption and external stimuli.

Findings

Most metallenes form buckled lattices, but a few like Na and Au form flat lattices under weak physisorption.

Biaxial tensile stress can reduce the adhesion strength needed to flatten a buckled lattice.

Electric fields can increase the threshold for flattening, offering controllable structural manipulation.

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' essential properties can only be retained in weak physisorption. Here, we study 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.

The structural behavior of atomically thin metallenes can be controlled by physisorption.

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