High-pressure synthesis of Dirac materials: layered van der Waals bonded BeN${}_4$ polymorph

Abstract

High pressure chemistry is known to inspire the creation of unexpected new classes of compounds with exceptional properties. Here we report the synthesis at ~90 GPa of novel beryllium polynitrides, monoclinic and triclinic BeN4. The triclinic phase, upon decompression to ambient conditions, transforms into a compound with atomic-thick BeN4 layers interconnected via weak van der Waals bonds consisting of polyacetylene-like nitrogen chains with conjugated π-systems and Be atoms in square-planar coordination. Theoretical calculations for a single BeN4 layer show that its electronic lattice is described by a slightly distorted honeycomb structure reminiscent of the graphene lattice and the presence of Dirac points in the electronic band structure at the Fermi level. The BeN4 layer, i.e. beryllonitrene, represents a qualitatively new class of 2D materials that can be built of a metal atom and polymeric nitrogen chains and host anisotropic Dirac fermions.

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Cited by in corpus (9)

• Ultrahigh stiffness and anisotropic Dirac cones in BeN4 and MgN4 monolayers: A first-principles study
• Anisotropic effects in two-dimensional materials
• Two-dimensional binary transition metal nitride $M$N${}_4$ ($M$ = V, Cr, Mn, Fe, Co) with a graphene-like structure and strong magnetic properties
• Lattice thermal conductivity and elastic modulus of XN4 (X=Be, Mg and Pt) 2D materials using machine learning interatomic potentials
• Prediction of single-atom-thick transition metal nitride CrN${}_4$ with a square-planar network and high-temperature ferromagnetism
• A Scheme to fabricate magnetic graphene-like cobalt nitride CoN4monolayer proposed by first-principles calculations
• Strong electron-phonon coupling and phonon-induced superconductivity in tetragonal C${}_3$N${}_4$ with hole doping
• High-temperature ferromagnetism and strong $\pi$-conjugation feature in two-dimensional manganese tetranitride
• Comment on A Dirac-semimetal two-dimensional BeN4: Thickness-dependent electronic and optical properties [Appl. Phys. Lett. 118, 203103 (2021)]