The stability of graphene-based Möbius strip with vacancy and at high-temperature

2018 ◽  
Vol 32 (31) ◽  
pp. 1850350
Author(s):  
Kaishuai Yang ◽  
Chuanguo Zhang ◽  
Xiaohong Zheng ◽  
Xianlong Wang ◽  
Zhi Zeng
Keyword(s):  
Density Functional ◽  
Md Simulations ◽  
Melting Behavior ◽  
Stable Configuration ◽  
Möbius Strip ◽  
Functional Theory ◽  
Melting Temperatures ◽  
Structural And Electronic Properties ◽  
The Stability ◽  
Mobius Strip

The structural and electronic properties of mono-vacancy (MV) defect in graphene-based Möbius strip (GMS) are studied in the framework of density functional theory (DFT) combined with the molecular dynamics (MD) simulations. Two kinds of MV defects are observed: the 59-type MV (a configuration with one pentagon and one nonagon ring) located at the curved areas of Möbius strip, and the 5566-type MV (a configuration with two pentagon and two hexagon rings) with one sp3 hybridized carbon appeared in the twisted areas. The 5566-type MV defect is the most stable configuration at 0 K, while the DFT-MD calculations show that it is unstable at room-temperature and will transform into a 59-type MV. Additionally, the melting behavior of GMSs is investigated through empirical potential MD simulations, and we find that their melting temperatures are about 2750 K, which is lower than that of carbon nanotubes and graphene.

First-Principle Studies on the Stability of AlN(0001)/NbB2(0001) Interface

2014 ◽  
Vol 1052 ◽  
pp. 18-23
Author(s):  
Hui Zhao ◽  
Kai Yuan Liu ◽  
Qian Han
Keyword(s):  
Density Functional Theory ◽  
Energy Density ◽  
Density Functional ◽  
Stable Configuration ◽  
Stable Model ◽  
First Principle ◽  
Total Energy Density ◽  
Energy Density Functional ◽  
Functional Theory ◽  
The Stability

The stability behaviour of AlN(0001)/NbB2(0001) interface was calculated by first-principle total-energy density functional theory. The calculation indicated that the stable NbB2(0001) surface is B terminated. We joined the AlN(0001) slab and the NbB2(0001) slab with different terminations together to construct all possible AlN(0001)/NbB2(0001) interface models, and calculated their interface energies to confirm the relatively stable model. We concluded that the structure with Al is on top of B in the interface AlN (0001)/NbB2(0001) is the most stable configuration.

STRONGLY AND WEAKLY INTERACTING CONFIGURATIONS OF HEXAGONAL BORON NITRIDE ON NICKEL

2015 ◽  
Vol 22 (06) ◽  
pp. 1550078 ◽  
Author(s):  
ABBAS EBNONNASIR ◽  
SUNEEL KODAMBAKA ◽  
CRISTIAN V. CIOBANU
Keyword(s):  
Density Functional Theory ◽  
Boron Nitride ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Density Functional Theory Calculations ◽  
Stable Configuration ◽  
Weakly Bound ◽  
Functional Theory ◽  
The Stability ◽  
Insulating Properties

Using density functional theory calculations with van der Waals corrections, we have investigated the stability and electronic properties of monolayer hexagonal boron nitride (hBN) on the Ni (111) surface. We have found that hBN can bind either strongly (chemisorption) or weakly to the substrate with metallic or insulating properties, respectively. While the more stable configuration is the chemisorbed structure, many weakly bound (physisorbed) states can be realized via growth around an hBN nucleus trapped in an off-registry position. This finding provides an explanation for seemingly contradictory sets of reports on the configuration of hBN on Ni (111).

scholarly journals Exploring the stability and electronic structure of beryllium and sulphur co-doped graphene: a first principles study

RSC Advances ◽  
2016 ◽  
Vol 6 (91) ◽  
pp. 88392-88402 ◽  
Author(s):  
O. Olaniyan ◽  
R. E. Mapasha ◽  
D. Y. Momodu ◽  
M. J. Madito ◽  
A. A. Kahleed ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Graphene Sheets ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Doped Graphene ◽  
The Stability ◽  
Co Doped

First principles density functional theory calculations have been performed to explore the stability, structural and electronic properties of Be and S co-doped graphene sheets.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Site preference and atomic ordering in the ternary Rh5Ga2As: first-principles calculations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nilanjan Roy ◽  
Sucharita Giri ◽  
Harshit ◽  
Partha P. Jana
Keyword(s):  
Total Energy ◽  
First Principles ◽  
Density Functional ◽  
Structure Type ◽  
Site Preference ◽  
X Ray Diffraction ◽  
Atomic Ordering ◽  
Functional Theory ◽  
The Stability ◽  
Bonding Characteristics

Abstract The site preference and atomic ordering of the ternary Rh5Ga2As have been investigated using first-principles density functional theory (DFT). An interesting atomic ordering of two neighboring elements Ga and As reported in the structure of Rh5Ga2As by X-ray diffraction data only is confirmed by first-principles total-energy calculations. The previously reported experimental model with Ga/As ordering is indeed the most stable in the structure of Rh5Ga2As. The calculation detected that there is an obvious trend concerning the influence of the heteroatomic Rh–Ga/As contacts on the calculated total energy. Interestingly, the orderly distribution of As and Ga that is found in the binary GaAs (Zinc-blende structure type), retained to ternary Rh5Ga2As. The density of states (DOS) and Crystal Orbital Hamiltonian Population (COHP) are calculated to enlighten the stability and bonding characteristics in the structure of Rh5Ga2As. The bonding analysis also confirms that Rh–Ga/As short contacts are the major driving force towards the overall stability of the compound.

scholarly journals Measuring the structure and equation of state of polyethylene terephthalate at megabar pressures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Lütgert ◽  
J. Vorberger ◽  
N. J. Hartley ◽  
K. Voigt ◽  
M. Rödel ◽  
...  
Keyword(s):  
Equation Of State ◽  
Polyethylene Terephthalate ◽  
Density Functional ◽  
Equations Of State ◽  
Md Simulations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Shock Hugoniot ◽  
Highly Correlated

AbstractWe present structure and equation of state (EOS) measurements of biaxially orientated polyethylene terephthalate (PET, $$({\hbox {C}}_{10} {\hbox {H}}_8 {\hbox {O}}_4)_n$$ ( C 10 H 8 O 4 ) n , also called mylar) shock-compressed to ($$155 \pm 20$$ 155 ± 20 ) GPa and ($$6000 \pm 1000$$ 6000 ± 1000 ) K using in situ X-ray diffraction, Doppler velocimetry, and optical pyrometry. Comparing to density functional theory molecular dynamics (DFT-MD) simulations, we find a highly correlated liquid at conditions differing from predictions by some equations of state tables, which underlines the influence of complex chemical interactions in this regime. EOS calculations from ab initio DFT-MD simulations and shock Hugoniot measurements of density, pressure and temperature confirm the discrepancy to these tables and present an experimentally benchmarked correction to the description of PET as an exemplary material to represent the mixture of light elements at planetary interior conditions.

scholarly journals The stability and electronic and photocatalytic properties of the ZnWO4 (010) surface determined from first-principles and thermodynamic calculations

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23477-23490
Author(s):  
Yonggang Wu ◽  
Jihua Zhang ◽  
Bingwei Long ◽  
Hong Zhang
Keyword(s):  
Phase Diagram ◽  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Thermodynamic Calculations ◽  
Photocatalytic Properties ◽  
Thermodynamic Approach ◽  
Functional Theory ◽  
Stability Phase Diagram ◽  
The Stability

The ZnWO4 (010) surface termination stability is studied using a density functional theory-based thermodynamic approach. The stability phase diagram shows that O-Zn, DL-W, and DL-Zn terminations of ZnWO4 (010) can be stabilized.

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