Stability and Elasticity of Quasi-Hexagonal Fullerene Monolayer from First-Principles Study

Abstract

As a newly synthesized two-dimensional carbon material, the stability study of monolayer fullerene networks or quasi-hexagonal phase fullerenes (qhp-C60) is timely desirable. We have investigated the stabilities of qhp-C60, including thermal, structural, mechanical, and thermodynamic stabilities, as well as the bonding characteristics, ductility, and mechanical properties, via first-principles calculations. The results show that qhp-C60 is energetically, mechanically, and thermodynamically stable. The thermodynamic stability of qhp-C60 at 300 K and 600 K is verified. The bonding characteristics of qhp-C60 are analyzed from the bond length, and it has sp2 and sp3 hybridization. The Pugh ratio (B/G) and Poisson’s ratio (v) indicate similar ductility with graphite and graphene. We also found that qhp-C60 has the lowest hardness and the anisotropy of the material. In addition, the electronic characteristics, including electron localization function (ELF), crystal orbital Hamiltonian population (COHP), and density of states (DOS) at different temperatures, are analyzed to verify the thermal stability of the material. Our results might be helpful in the material design of qhp-C60-related applications.