Contrasting Elastic Properties of Heavily B- and N-doped Graphene with Random Impurity Distributions Including Aggregates

Abstract

We focused on elastic properties of B-and N-doped graphene in wide range of concentrations up to 20%. The Young's, bulk and shear moduli and Poisson's ratio have been calculated by means of the density functional theory for a representative set of supercells with disordered impurity patterns including aggregates. In contrast to earlier work, it is demonstrated that doping with nitrogen even strengthens the graphene layers, whereas incorporation of boron induces large structural and morphological changes seen in simulated STM images. Young's and shear moduli increase or decrease with the doping strength for nitrogen or boron, respectively, while bulk modulus and Poisson's ratio exhibit opposite trends. Elastic properties of samples for both types of impurities are strongly related to the electronic structures, especially for heavy doping (>12%). Local arrangements of dopants and an agregation or separation of impurities play crucial role in the determination of stiffness in the investigated systems. Interestingly, these findings are opossed for B-and N-contained samples.

Mechanical properties and thermal conductivity of graphitic carbon nitride: A molecular dynamics study

“…In our previous work, we studied the mechanical response of nitrogen doped graphene. Interestingly, recent density functional theory study [26] confirms the accuracy of our predictions for mechanical properties of nitrogen doped graphene. We note that the time increment of all simulations was fixed at 0.5 fs.…”

Assessment of the mechanical properties of monolayer graphene using the energy and strain-fluctuation methods

“…4. We calculated the Young's modulus and Poisson's ratio of the graphene sheet using eqn (7) and (8), and the analysis shows a decrease in those elastic physical quantities with an increase in temperature, as shown in Fig. 5(a) and (b), respectively.…”

“…6 The semimetallic character and unique electronic properties of graphene can be effectively used in high-speed integrated devices, eld effect transistors, gas sensors, exible electronics, supercapacitors, and nano-composites. 7,8 An understanding of the temperature-dependent physical properties of materials is a prerequisite for advanced devicefabrication technology. Several groups have performed atomistic simulations and experimental analyses to calculate the mechanical properties of monolayer graphene.…”

Negative thermal expansion of pure and doped graphene

“…Hence we obtained surface bulk modulus as defined by us (equation 5) for pure graphene to be equal to 90.24 N/m. The bulk modulus of graphene has earlier been studied by many authors [34][35][36][37]. Reich et al [34] have reported a bulk modulus value of 700GPa and Milowaska et.…”

“…al. [37] has reported a value of 528 GPa for pure graphene. It may be noted that for calculation of volume of the unit cell they take thickness of the cell around 3.4 Å.…”