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Using a starlike Be 6 Au 7 − cluster as a building block and following the bottom-up strategy, an intriguing two-dimensional (2D) binary s-block metal Be 2 Au monolayer with a P 6/ mmm space group was theoretically designed. Both the Be 6 Au 7 − cluster and the 2D monolayer are global minima featuring rule-breaking planar hexacoordinate motifs (anti-van't Hoff/Le Bel arrangement), and their high stabilities are attributed to good electron delocalization and electronic-stabilization-induced steric force. Strikingly, the Be 2 Au monolayer is a rare Dirac material with two perfect Dirac node-loops in the band structure and is a phonon-mediated superconductor with a critical temperature of 4.0 K. The critical temperature can be enhanced up to 11.0 K by applying compressive strain at only 1.6%. This study not only identifies a new binary s-block metal 2D material, namely Be 2 Au, which features planar hexacoordination, and a candidate superconducting material for further explorations, but also provides a new strategy to construct 2D materials with novel chemical bonding.
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CuB monolayer: a novel 2D anti-van’t Hoff/Le Bel nanostructure with planar hyper-coordinate boron/copper and superconductivity
To achieve specific applications, it is always desirable to design new materials with peculiar topological properties. Herein, based on a D2h B2Cu6H6 molecule with the unique chemical bonding of planar pentacoordinate boron (ppB) as a building block, we constructed an infinite CuB monolayer by linking B2Cu6 subunits in an orthorhombic lattice. The planarity of the CuB sheet is attributed to the multicenter bonds and electron donation-back donation, as revealed by chemical bonding analysis. As a global minimum confirmed by the particle swarm optimization method, the CuB monolayer is expected to be highly stable, as indicated by its rather high cohesive energy, absence of soft phonon modes, and good resistance to high temperature, and thus is highly feasible for experimental realization. Remarkably, this CuB monolayer is metallic and predicted to be superconducting with an estimated critical temperature (Tc) of 4.6 K, and the critical temperature could be further enhanced by tensile strains (to 21 K at atmospheric pressure).
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- Award ID(s):
- 1849243
- PAR ID:
- 10407202
- Date Published:
- Journal Name:
- Journal of Materials Informatics
- Volume:
- 2
- Issue:
- 3
- ISSN:
- 2770-372X
- Page Range / eLocation ID:
- 13
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.20517/jmi.2022.10
