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

2021 ◽  
Vol 7 (1) ◽  
pp. 8
Author(s):  
Teerachote Pakornchote ◽  
Annop Ektarawong ◽  
Udomsilp Pinsook ◽  
Thiti Bovornratanaraks
Keyword(s):  
Bulk Modulus ◽  
Band Gap ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Structural Models ◽  
Type Structure ◽  
Two Dimensional ◽  
Dangling Bonds ◽  
N Content ◽  
Nitrogen Substitution

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.

Temperature Dependences of the Elastic Constants of Precipitation-Hardened Aluminum Alloys 2014 and 2219

1977 ◽  
Vol 99 (2) ◽  
pp. 181-184 ◽  
Author(s):  
D. T. Read ◽  
H. M. Ledbetter
Keyword(s):  
Aluminum Alloys ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Temperature Dependence ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Ultrasonic Pulse ◽  
Young’S Moduli ◽  
Temperature Dependences ◽  
Sound Velocities

Elastic properties of precipitation-hardened aluminum alloys 2014 and 2219 were studied between 4 and 300 K using ultrasonic pulse techniques. Both the longitudinal and transverse sound velocities were measured. Also reported are the Young’s modulus, shear modulus, bulk modulus, and Poisson’s ratio. For both alloys, the Young’s moduli are about ten percent higher than for unalloyed aluminum, and they increase about ten percent on cooling from 300 to 4 K. All the elastic constants show normal temperature dependence.

First-Principles Calculations of Elastic Properties of HoBi and ErBi

2013 ◽  
Vol 664 ◽  
pp. 672-676
Author(s):  
De Ming Han ◽  
Gang Zhang ◽  
Li Hui Zhao
Keyword(s):  
Shear Modulus ◽  
Physical Properties ◽  
Bulk Modulus ◽  
Elastic Properties ◽  
Lattice Constant ◽  
Elastic Constants ◽  
First Principles ◽  
Energy Band ◽  
First Principles Calculations ◽  
Future Work

We present first-principles investigations on the elastic properties of XBi (X=Ho, Er) compounds. Basic physical properties, such as lattice constant, elastic constants (Cij), isotropic shear modulus (G), bulk modulus (B), Young’s modulus (Y), Poisson’s ratio (υ), and Anisotropy factor (A) are calculated. The calculated energy band structures show that the two compounds possess semi-metallic character. We hope that these results would be useful for future work on two compounds.

scholarly journals First Principles Study on the Structural, Elastic, Electronic and Optical Properties of Cubic ‘Half-Heusler’ Alloy RuVAs Under Pressure

2020 ◽  
pp. 51-63 ◽  
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Bulk Modulus ◽  
Band Gap ◽  
Elastic Constants ◽  
First Principles ◽  
Theoretical Data ◽  
Lattice Parameter ◽  
Electronic Band ◽  
Electronic And Optical Properties

The pressure effect (0 to 40 GPa) on the structural, elastic, electronic, and optical properties of half-metallic compound RuVAs has been investigated employing the DFT based on the first-principles method. The CASTEP computer code is used for this investigation. The calculated lattice parameter show slide deviation from the synthesized and other theoretical data. The normalized lattice parameter and volume are decreased with increasing pressure. The zero pressure elastic constants and also the pressure-dependent elastic constants are positive up to 40 GPa and satisfy the Born stability condition which ensured that the compound RuVAs is stable in nature. At zero pressure, the electronic band gap of 0.159 eV is observed from the band structure calculations which ensured the semimetallic nature of RuVAs. No band gap is observed in the electronic band structure at 40 GPa which indicates the occurrence of phase transition of compound RuVAs at this pressure. We have calculated the value of bulk modulus B, shear modulus G, Young’s modulus E, Pugh ratio B/G, Poisson’s ratio ν and anisotropy factor A of this compound by using the Voigt-Reuss-Hill (VRH) averaging scheme under pressure. The bulk modulus shows a linear response to pressure so that the hardness of this material is increased with increasing pressure. Furthermore, the optical properties such as reflectivity, absorptivity, conductivity, dielectric constant, refractive index, and loss function of RuVAs were evaluated and discussed under pressure up to 40 GPa.

Tunable band gap and hydrogen adsorption property of a two-dimensional porous polymer by nitrogen substitution

2013 ◽  
Vol 15 (2) ◽  
pp. 666-670 ◽  
Author(s):  
Ruifeng Lu ◽  
Zhaoshun Meng ◽  
Erjun Kan ◽  
Feng Li ◽  
Dewei Rao ◽  
...  
Keyword(s):  
Band Gap ◽  
Hydrogen Adsorption ◽  
Adsorption Property ◽  
Porous Polymer ◽  
Two Dimensional ◽  
Nitrogen Substitution ◽  
Tunable Band Gap

Effect of Pressure on Structural, Electronic and Elastic Properties of Cubic (Pm3m) SnTiO3 Using First Principle Calculation

2012 ◽  
Vol 501 ◽  
pp. 342-346 ◽  
Author(s):  
M.F.M. Taib ◽  
M.K. Yaakob ◽  
Amreesh Chandra ◽  
Abdul Kariem Mohd Arof ◽  
M.Z.A. Yahya
Keyword(s):  
Band Gap ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Perovskite Oxide ◽  
First Principles Calculation ◽  
Cubic Phase ◽  
Electronic Band

The electronic band structure, density of state and elastic properties of lead-free perovskite oxide SnTiO3 (ST) were investigated by employing first principles calculation using the Density Functional Theory (DFT) within local density approximation (LDA). The energy band gap was calculated from the separation between the Ti 3d (conduction band) and the maximum of O 2p (valence band). This gives an indirect band gap of 2.36 eV. The elastic constants and their pressure dependence were calculated up to 30 GPa and the independent elastic constants (C11, C12, and C44), bulk modules, B were obtained and analyzed. The results showed that SnTiO3 have a mechanical stability in cubic phase (Pm3m).

Effect of Cd Doping on Mechanical Properties of SrCoO3

2014 ◽  
Vol 975 ◽  
pp. 163-167 ◽  
Author(s):  
N.K. Gaur ◽  
Rasna Thakur ◽  
Rajesh K. Thakur ◽  
A.K. Nigam
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Anisotropy Parameter ◽  
Cd Doping ◽  
First Time ◽  
Rigid Ion Model

We have investigated the elastic and thermal properties of Sr1-xCdxCoO3 (0=x=0.1) probably for the first time by means of modified rigid ion model (MRIM). In this paper, we present the second order elastic constants (SOECs) and other elastic properties like Bulk modulus (B), Young's modulus (Y), Shear modulus (G), ̠̹̿̓̓̿̾˷̓˰̱̹͂̈́̿˰˸σ˹˼˰̵̜̱̽˷̓˰̵̵̱̱̀͂̽̈́͂˰˸m, l), transverse, longitudinal, ˰̵̷̵̱̱͆͂˰̵͇̱͆˰̵̼̳̹͉͆̿̈́˰˰˸υt, υl˼˰υm) and Anisotropy parameter (A). Here, the SOECs for Sr1-xCdxCoO3 compounds are positive and satisfy the generalized criteria for mechanically stable crystals: (C11-C12) > 0, (C11+2C12) > 0 and C44 > 0 which confirm that Sr1-xCdxCoO3 (0=x=0.1) belong to metallically bonding materials.

scholarly journals Structural, Electronic, Lattice Dynamic, and Elastic Properties of SnTiO3 and PbTiO3 Using Density Functional Theory

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Shiferaw Kuma ◽  
Menberu Mengesha Woldemariam
Keyword(s):  
Bulk Modulus ◽  
Elastic Properties ◽  
Density Of States ◽  
Elastic Constants ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Electronic Band Structure ◽  
Theoretical Data ◽  
Modern Theory ◽  
Electronic Band

The structural, electronic, and elastic properties of tetragonal phase of SnTiO3 and PbTiO3 are investigated using first principle calculations. The unknown exchange-correlation functional is approximated with generalized gradient approximation (GGA) as implemented in pseudopotential plane wave approach. The convergence test of total energy with respect to energy cutoff and k-point sampling is preformed to ensure the accuracy of the calculations. The structural properties such as equilibrium lattice constant, equilibrium unit cell volume, bulk modulus, and its derivative are in reasonable agreement with the previous experimental and theoretical works. From elastic constants, mechanical parameters such as anisotropy factor A, shear modulus G, bulk modulus B, Young’s modulus E, and Poison’s ratio n are determined by using Voigt–Reuss–Hill average approximation. In addition, Debye temperature and longitudinal and transversal sound velocities are predicted from elastic constants. The electronic band structure and density of states of both compounds are obtained and compared with the available experimental as well as theoretical data. Born effective charge (BEC), phonon dispersion curve, and density of states are computed from functional perturbation theory (DFPT). Lastly, the spontaneous polarization is determined from the modern theory of polarization, and they are in agreement with the previous findings.

Structural and elastic properties of TiN and AlN compounds: first-principles study

2014 ◽  
Vol 32 (2) ◽  
pp. 220-227 ◽  
Author(s):  
Meriem Fodil ◽  
Amine Mounir ◽  
Mohammed Ameri ◽  
Hadj Baltache ◽  
Bachir Bouhafs ◽  
...  
Keyword(s):  
Bulk Modulus ◽  
Elastic Properties ◽  
Rock Salt ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Data ◽  
Generalized Gradient ◽  
Tin Compounds ◽  
Shear Moduli

AbstractFirst-principles calculations of the lattice constants, bulk modulus, pressure derivatives of the bulk modulus and elastic constants of AlN and TiN compounds in rock-salt (B1) and wurtzite (B4) structures are presented. We have used the fullpotential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT) in the generalized gradient approximation (GGA) for the exchange-correlation functional. Moreover, the elastic properties of cubic TiN and hexagonal AlN, including elastic constants, bulk and shear moduli are determined and compared with previous experimental and theoretical data. Our results show that the structural transition at 0 K from wurtzite to rock-salt phase occurs at 10 GPa and −26 GPa for AlN and TiN, respectively. These results are consistent with those of other studies found in the literature.

A Natural Humidity Sensitive Two-dimensional Tunable Photonic Band Gap Material and its Optic Properties

2009 ◽  
Vol 24 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Wei-Gang ZHANG ◽  
Jun YAN ◽  
Gang WANG ◽  
Hao-Xuan LI ◽  
Gang-Sheng ZHANG
Keyword(s):  
Band Gap ◽  
Photonic Band Gap ◽  
Two Dimensional ◽  
Photonic Band Gap Material ◽  
Photonic Band

scholarly journals Generalization of intrinsic ductile-to-brittle criteria by Pugh and Pettifor for materials with a cubic crystal structure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
O. N. Senkov ◽  
D. B. Miracle
Keyword(s):  
Crystal Structure ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Single Crystal ◽  
Elastic Constants ◽  
Mechanical Analysis ◽  
Quantum Mechanical ◽  
Modulus Ratio ◽  
Cubic Crystal ◽  
The Difference

AbstractTwo classical criteria, by Pugh and Pettifor, have been widely used by metallurgists to predict whether a material will be brittle or ductile. A phenomenological correlation by Pugh between metal brittleness and its shear modulus to bulk modulus ratio was established more than 60 years ago. Nearly four decades later Pettifor conducted a quantum mechanical analysis of bond hybridization in a series of intermetallics and derived a separate ductility criterion based on the difference between two single-crystal elastic constants, C12–C44. In this paper, we discover the link between these two criteria and show that they are identical for materials with cubic crystal structures.

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