Possible nonplanar structure of phagraphene and its thermal stability

TL;DR

This paper investigates the stability of phagraphene, a predicted graphene allotrope, revealing its potential nonplanar structure and analyzing its defect formation and thermal stability through computational models.

Contribution

It demonstrates that phagraphene is nearly unstable in a planar form and explores its nonplanar configurations and defect dynamics using density functional theory and tight-binding models.

Findings

Phagraphene may adopt a nonplanar, wavy structure.

The nonplanar form is nearly degenerate in energy with the planar form.

Characteristic defect formation times depend on temperature.

Abstract

It is shown that phagraphene, a recently predicted planar allotrope of graphene with Dirac fermions, is unstable or, at least, almost unstable with respect to transverse atomic displacements. This result is obtained by numerical calculations in the framework of both the tight-binding model and the density functional theory. A nonplanar atomic configuration of phagraphene has a wavy shape and is almost degenerate in energy with the planar configuration. The main types of possible structural defects in phagraphene are determined. The temperature dependence of characteristic times of their formation is found.