Modifying Electronic and Elastic Properties of 2-Dimensional [110] Diamond by Nitrogen Substitution

Teerachote Pakornchote,Thiti Bovornratanaraks,Udomsilp Pinsook,Annop Ektarawong

doi:10.3390/c7010008

Teerachote Pakornchote, Thiti Bovornratanaraks + Show 2 more

Open Access

https://doi.org/10.3390/c7010008

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Abstract

One type of two-dimensional diamonds that are derived from [111] direction, so-called diamane, has been previously shown to be stabilized by N-substitution, where the passivation of dangling bonds is no longer needed. In the present work, we theoretically demonstrated that another type of two-dimensional diamonds derived from [110] direction exhibiting a washboard conformation can also be stabilized by N-substitution. Three structural models of washboard-like carbon nitrides with compositions of C6N2, C5N3, and C4N4 are studied together with the fully hydrogenated washboard-like diamane (C8H4). The result shows that the band gap of this type structure is only open the dangling bonds that are entirely diminished through N-substitution. By increasing the N content, the C11 and C22 are softer and the C33 is stiffer where their bulk modulus are in the same order, which is approximately 550 GPa. When comparing with the hydrogenated phase, the N-substituted phases have higher elastic constants and bulk modulus, suggesting that they are possibly harder than the fully hydrogenated diamane.

Highlights

Diamond, a carbon allotrope, is a material that has been reported to be the first hardest material and it possesses the highest thermal conductivity
A 2D diamond that is derived from the bulk diamond thinned down in [111] direction or diamane is a promising material for adopting the property of its bulk counterpart, diamond, but its thickness is only 4 C
The sp2 carbon film can be indented by a sharp indenter creating the sp3 hybridization and showing that the indented multi-layer graphene is harder if its number of layers is fewer [10,12,13]

Summary

Introduction

A carbon allotrope, is a material that has been reported to be the first hardest material and it possesses the highest thermal conductivity. The sp carbon film can be indented by a sharp indenter creating the sp hybridization and showing that the indented multi-layer graphene is harder if its number of layers is fewer [10,12,13]. We have shown that the passivation of dangling bonds of the surficial C atoms is not the only method for stabilizing diamane. It can be stabilized by substituting the. Because its surfaces are washboard conformations [25], it will be represented as W-diamane for a phase with x = 0 and N-subsituted W-diamanes for phases with x = 2, 3, 4 Their elastic and electronic properties are investigated, due to a number of N atoms in the structure. The θ indicates to the angle measured between surficial and inner atoms. (e) Paths between high symmetry points in the Brillouin zone

Computational Method

Results

Electronic Property and Bonding

Elastic Constants

Formation Energy

Conclusions