Glitter in a 2D monolayer

Abstract

We predict a highly stable and robust atomically thin gold monolayer with a hexagonal close packed lattice stabilized by metallic bonding with contributions from strong relativistic effects and aurophilic interactions. We have shown that the framework of the Au monolayer can survive 10 ps MD annealing simulations up to 1400 K. The framework is also able to survive large motions out of the plane. Due to the smaller number of bonds per atom in the 2D layer compared to the 3D bulk we observe significantly enhanced energy per bond (0.94 vs. 0.52 eV per bond). This is similar to the increase in bond strength going from 3D diamond to 2D graphene. It is a non-magnetic metal, and was found to be the global minima in the 2D space. Phonon dispersion calculations demonstrate high kinetic stability with no negative modes. This 2D gold monolayer corresponds to the top monolayer of the bulk Au(111) face-centered cubic lattice. The close-packed lattice maximizes the aurophilic interactions. We find that the electrons are completely delocalized in the plane and behave as 2D nearly free electron gas. We hope that the present work can inspire the experimental fabrication of novel free standing 2D metal systems.

Computational Prediction of the Low‐Temperature Ferromagnetic Semiconducting 2D SiN Monolayer

“…Both experimental and theoretical results show fascinating properties. Furthermore, on the basis of electronic and geometric fits, a series of planar hypercoordinate monolayers have been predicted, such as, Cu 2 Ge, Ni 2 Si/Ge, Cu 2 P/As, and transition metal monolayers (Cu, Ag, Au, Pt). Quite recently, a brand‐new 2D aluminum boride (AlB 6 −ptAl−array) nanosheet with a planar tetracoordinate aluminum (ptAl) array was predicted to be a highly stable superconductive material with triple Dirac cones .…”

Atlas for the properties of elemental two-dimensional metals

“…Similarly, free-standing monolayer-thick zinc oxide [31] and copper oxide [32] membranes have been observed inside graphene nanopores. In addition to these 2D structures, * pekka.koskinen@iki.fi theoretical works have predicted the existence of stable 2D gold [33], silver [34], and copper [35] membranes. Further, a computational study found that Au membranes may form in graphene nanopores by way of only small energy barriers for Au diffusion [36].…”

Metallic and Magnetic 2D Materials Containing Planar Tetracoordinated C and N

“…Another possible structure could be inspired by the recent work of Yang et al on a graphene-like structure for Ni 2 Ge and Ni 2 Si 2D materials, where Ge/Si resides in the center of the Ni 6 hexagon. 46 Although our MD simulations never reached this phase, we manually tested it for Co 2 C, Co 2 N, Ni 2 C, and Ni 2 N ( Figure 2B). The relative energies of the studied phases ( Table 2) are indicative of the high preference of nitrides for the p4g reconstructed phase.…”