scholarly journals First-Principles Investigation of Mechanical Behavior of B2 Type Aluminides: Feal and Nial

1990 ◽  
Vol 213 ◽  
Author(s):  
C. L. Fu ◽  
M. H. Yoo
Keyword(s):  
Charge Transfer ◽  
First Principles ◽  
Boundary Energy ◽  
Bond Formation ◽  
Antiphase Boundary ◽  
Repulsive Interaction ◽  
First Principles Calculations ◽  
Partial Dislocations ◽  
Cleavage Strength ◽  
Fe Sites

ABSTRACTFirst-principles calculations of the elastic constants, shear fault energies, and cleavage strength of NiAl and FeAl are presented. For NiAl, we find that the dissociation of <111> superdislocations into partial dislocations is unlikely, because of a high antiphase boundary energy and a weak repulsive elastic force between partial dislocations. FeAl has a high ideal cleavage strength as a result of the directional d-bond formation at the Fe sites. The strong ordering behavior of NiAl is explained in terms of the Al-to-Ni charge transfer and the repulsive interaction between Al atoms. The spontaneous glide decomposition of the <111> superdislocations in NiAl is also discussed.

scholarly journals Temperature Effects on the Elastic Constants, Stacking Fault Energy and Twinnability of Ni3Si and Ni3Ge: A First-Principles Study

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 364 ◽  
Author(s):  
Lili Liu ◽  
Liwan Chen ◽  
Youchang Jiang ◽  
Chenglin He ◽  
Gang Xu ◽  
...  
Keyword(s):  
Elastic Constants ◽  
First Principles ◽  
Antiphase Boundary ◽  
Stacking Fault ◽  
First Principles Calculations ◽  
Planar Fault ◽  
Different Temperatures ◽  
Generalized Stacking Fault ◽  
Increasing Temperature ◽  
Stacking Fault Energies

The volume versus temperature relations for Ni 3 Si and Ni 3 Ge are obtained by using the first principles calculations combined with the quasiharmonic approach. Based on the equilibrium volumes at temperature T, the temperature dependence of the elastic constants, generalized stacking fault energies and generalized planar fault energies of Ni 3 Si and Ni 3 Ge are investigated by first principles calculations. The elastic constants, antiphase boundary energies, complex stacking fault energies, superlattice intrinsic stacking fault energies and twinning energy decrease with increasing temperature. The twinnability of Ni 3 Si and Ni 3 Ge are examined using the twinnability criteria. It is found that their twinnability decrease with increasing temperature. Furthermore, Ni 3 Si has better twinnability than Ni 3 Ge at different temperatures.

scholarly journals Rich p -type-doping phenomena in boron-substituted silicene systems

2020 ◽  
Vol 7 (12) ◽  
pp. 200723
Author(s):  
Hai Duong Pham ◽  
Wu-Pei Su ◽  
Thi Dieu Hien Nguyen ◽  
Ngoc Thanh Thuy Tran ◽  
Ming-Fa Lin
Keyword(s):  
Charge Transfer ◽  
Fermi Level ◽  
Charge Density ◽  
Electronic Properties ◽  
First Principles ◽  
Chemical Environment ◽  
First Principles Calculations ◽  
Density Distributions ◽  
Essential Properties ◽  
P Type

The essential properties of monolayer silicene greatly enriched by boron substitutions are thoroughly explored through first-principles calculations. Delicate analyses are conducted on the highly non-uniform Moire superlattices, atom-dominated band structures, charge density distributions and atom- and orbital-decomposed van Hove singularities. The hybridized 2 p z –3 p z and [2s, 2 p x , 2 p y ]–[3s, 3 p x , 3 p y ] bondings, with orthogonal relations, are obtained from the developed theoretical framework. The red-shifted Fermi level and the modified Dirac cones/ π bands/ σ bands are clearly identified under various concentrations and configurations of boron-guest atoms. Our results demonstrate that the charge transfer leads to the non-uniform chemical environment that creates diverse electronic properties.

scholarly journals Ab-Initio Study of the Electronic and Magnetic Properties of Boron- and Nitrogen-Doped Penta-Graphene

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 816 ◽  
Author(s):  
Chao Zhang ◽  
Yu Cao ◽  
Xing Dai ◽  
Xian-Yong Ding ◽  
Leilei Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Charge Transfer ◽  
First Principles ◽  
Magnetic Moments ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Magnetic Devices ◽  
Spin Polarized ◽  
Electronic Band Gap ◽  
Transfer Mechanisms

First-principles calculations were performed to investigate the effects of boron/nitrogen dopant on the geometry, electronic structure and magnetic properties of the penta-graphene system. It was found that the electronic band gap of penta-graphene could be tuned and varied between 1.88 and 2.12 eV depending on the type and location of the substitution. Moreover, the introduction of dopant could cause spin polarization and lead to the emergence of local magnetic moments. The main origin of the magnetic moment was analyzed and discussed by the examination of the spin-polarized charge density. Furthermore, the direction of charge transfer between the dopant and host atoms could be attributed to the competition between the charge polarization and the atomic electronegativity. Two charge-transfer mechanisms worked together to determine which atoms obtained electrons. These results provide the possibility of modifying penta-graphene by doping, making it suitable for future applications in the field of optoelectronic and magnetic devices.

Band alignment and charge transfer predictions of ZnO/ZnX (X = S, Se or Te) interfaces applied to solar cells: a PBE+U theoretical study

2018 ◽  
Vol 20 (7) ◽  
pp. 4953-4961 ◽  
Author(s):  
Efracio Mamani Flores ◽  
Rogério Almeida Gouvea ◽  
Maurício Jeomar Piotrowski ◽  
Mário Lucio Moreira
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
First Principles ◽  
Theoretical Study ◽  
Band Alignment ◽  
First Principles Calculations

We performed first-principles calculations within PBE and PBE+U approximations to study ZnO and ZnX bulk systems and ZnO/ZnX interfaces (X = S, Se or Te), to the better comprehension of charge transference through the interface.

Adsorption of Methane on Pristine and Al-Doped Graphene: A Comparative Study via First-Principles Calculation

2012 ◽  
Vol 602-604 ◽  
pp. 870-873 ◽  
Author(s):  
Wei Zhao ◽  
Qing Yuan Meng
Keyword(s):  
Charge Transfer ◽  
Binding Energy ◽  
Comparative Study ◽  
First Principles ◽  
First Principles Calculation ◽  
Pristine Graphene ◽  
First Principles Calculations ◽  
Graphene Surface ◽  
Doped Graphene ◽  
Adsorption Of Methane

The adsorption of methane (CH4) molecule on the pristine and Al-doped (4, 8) graphene was investigated via the first-principles calculations. The results demonstrated that, in comparison to the adsorption of a CH4molecule on the pristine graphene sheet, a relatively stronger adsorption was observed between the CH4molecule and Al-doped graphene with a shorter adsorption distance, larger binding energy and more charge-transfer from the graphene surface to the CH4molecule. Therefore, the Al-doped graphene can be expected to be a novel sensor for the detection of CH4molecules in future applications.

Low-pressure superconductivity in lithium-doped methane predicted by first principles

2020 ◽  
pp. 2150032
Author(s):  
Ning Lu ◽  
Yu-Long Hai ◽  
Hai-Yan Lv ◽  
Wen-Jie Li ◽  
Chun-Lei Yang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
High Temperature ◽  
Crystal Field ◽  
First Principles ◽  
Pressure Range ◽  
High Temperature Superconductor ◽  
Low Pressure ◽  
First Principles Calculations ◽  
A Charge ◽  
Low Pressures

To explore the high-temperature superconductor at low pressures, we have investigated the crystal structures, electronic properties, and possible superconductivity in the case of methane (CH4) doped by lithium in the pressure range of [Formula: see text][Formula: see text]GPa, based on the first-principles calculations. The results show that Li-intercalated CH4 (Lix(CH4)[Formula: see text]) can realize metallization and superconductivity at low pressures, even 5[Formula: see text]GPa. We find that there is a charge transfer between Li and CH4, but the metallization is driven by the change of crystal field induce by doping instead of charge transfer. The critical temperture is predicted from 3.8[Formula: see text]K at 5[Formula: see text]GPa for LiCH4 to 12.1[Formula: see text]K at 100[Formula: see text]GPa for Li(CH4)4. The low-pressure superconductivity of Lix(CH4)[Formula: see text] can be further optimized by adjusting component and pressure.

Thermoelectric properties of organic charge transfer salts from first-principle investigations: Role of molecular packing and triiodide anions

2022 ◽  
Author(s):  
Yishan Wang ◽  
Meng Zhao ◽  
Hu Zhao ◽  
Shuzhou Li ◽  
Jia Zhu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
First Principles ◽  
Transport Theory ◽  
Deformation Potential ◽  
First Principles Calculations ◽  
Boltzmann Transport ◽  
Boltzmann Transport Theory ◽  
Charge Transfer Salts ◽  
Deformation Potential Theory

The potency of charge transfer (CT) salts in thermoelectric (TE) applications based on (5-CNB-EDT-TTF)4I3 is systematically explored by first-principles calculations combined with Boltzmann transport theory and deformation potential theory, focusing...

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