scholarly journals An ab initio study of structural, elastic and electronic properties of hexagonal MAuGe (M = Lu, Sc) compounds

2021 ◽  
Vol 24 (1) ◽  
pp. 13706
Author(s):  
R. Radjai ◽  
N. Guechi ◽  
D. Maouche
Keyword(s):  
Electronic Properties ◽  
Elastic Constants ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
Structural Parameters ◽  
Theoretical Method ◽  
Generalized Gradient ◽  
Plane Wave Method ◽  
Density Distributions ◽  
Densities Of States

In this paper, we performed a detailed theoretical study of structural, elastic and electronic properties of two germanides LuAuGe and ScAuGe by means of first-principles calculations using the pseudopotential plane-wave method within the generalized gradient approximation. The crystal lattice parameters and the internal coordinates are in good agreement with the existing experimental and theoretical reports, which proves the reliability of the applied theoretical method. The hydrostatic pressure effect on the structural parameters is shown. The monocrystalline elastic constants were calculated using the stress-strain technique. The calculated elastic constants of the MAuGe (M = Lu, Sc) compounds meet the mechanical stability criteria for hexagonal crystals and these constants were used to analyze the elastic anisotropy of the MAuGe compounds through three different indices. Polycrystalline isotropic elastic moduli, namely bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and the related properties are also estimated using Voigt-Reuss-Hill approximations. Finally, we studied the electronic properties of the considered compounds by calculating their band structures, their densities of states and their electron density distributions.

scholarly journals First-principle investigations of structural and electronic properties of TMAl (TM = Fe, Co, and Ni) transition metal aluminides

2015 ◽  
Vol 33 (2) ◽  
pp. 251-258
Author(s):  
Bendouma Doumi ◽  
Allel Mokaddem ◽  
Mustapha Ishak-Boushaki ◽  
Miloud Boutaleb ◽  
Abdelkader Tadjer
Keyword(s):  
Transition Metal ◽  
Electronic Properties ◽  
Density Functional ◽  
First Principle ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Plane Wave Method ◽  
Structural And Electronic Properties ◽  
The Difference ◽  
Metal Aluminides

AbstractIn the present work, we have investigated the structural and electronic properties of TMAl (TM = Fe, Co, and Ni) transition metal aluminides in the B2 structure, using first-principle calculations of the density functional theory (DFT) based on the linearized augmented plane wave method (FP-LAPW) as implemented in the WIEN2k code, in which the energy of exchange and correlation are treated by the generalized gradient approximation (GGA), proposed in 1996 by Perdew, Burke and Ernzerhof (PBE). The ground state properties have been calculated and compared with other calculations, and the electronic structures of all FeAl, CoAl, and NiAl compounds exhibited a metallic behavior. It was depicted that the density of states is characterized by the large hybridization between the s-p (Al) and 3d (Fe, Co, and Ni) states, which creates the pseudogap in the region of anti-bonding states. Moreover, the band structures of FeAl, CoAl, and NiAl are similar to each other and the difference between them is in the energy level of each band relative to the Fermi level.

Electronic properties of austenite and martensite Fe-9%Mn alloys

Open Physics ◽  
2008 ◽  
Vol 6 (4) ◽  
Author(s):  
Ercan Uçgun ◽  
Hamza Ocak
Keyword(s):  
Total Energy ◽  
Electronic Properties ◽  
Lattice Relaxation ◽  
The Self ◽  
Full Potential ◽  
Generalized Gradient ◽  
Plane Wave Method ◽  
Lattice Constants ◽  
Generalized Gradient Approximation ◽  
Self Consistent

AbstractWe calculate the electronic properties of austenite and martensite Fe-9%Mn alloys using the self consistent full-potential linearized-plane-wave method under the generalized gradient approximation full lattice relaxation. By minimizing total-energy, the lattice constants in their ground states were determined. We discuss the total energy dependence of the volume, and density of states (DOS).

First-principles calculations of the structural, elastic, mechanical, electronic and optical properties of monoclinic Hf4CuSi4

2020 ◽  
Vol 34 (06) ◽  
pp. 2050035
Author(s):  
Xia Xu ◽  
Wei Zeng ◽  
Fu-Sheng Liu ◽  
Zheng-Tang Liu ◽  
Qi-Jun Liu
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
Structural Parameters ◽  
Functional Theory ◽  
Text Structures ◽  
Structure Density

In this paper, the structural, electronic, elastic, mechanical and optical properties of monoclinic [Formula: see text] are studied using the first-principles density functional theory (DFT). The calculated structural parameters are consistent with the experimental data. The elastic constants of [Formula: see text] structures are calculated, indicating that [Formula: see text] shows mechanical stability and elastic anisotropy. According to the [Formula: see text] and Poisson’s ratio, monoclinic [Formula: see text] shows a brittle manner. The energy band structure, density of states, charge transfers and bond populations are given. And the band structure shows that the material is a metal conductor. Moreover, the optical properties and optical anisotropy of [Formula: see text] are shown and analyzed.

First-Principles Calculations of Structural, Electronic, Magnetic and Elastic Properties of Heusler Alloys Ru2CoZ (Z = Si, Ge and Sn)

SPIN ◽  
2018 ◽  
Vol 08 (03) ◽  
pp. 1850009 ◽  
Author(s):  
O. Baraka ◽  
S. Amari ◽  
A. Yakoubi
Keyword(s):  
Elastic Constants ◽  
Density Functional ◽  
Heusler Alloys ◽  
Local Magnetic Moment ◽  
Heat Of Formation ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Linearized Augmented Plane Wave

Structural, elastic, electronic and magnetic properties of Ru2Co[Formula: see text] ([Formula: see text], Ge and Sn) alloys are investigated by using potentially linearized augmented plane-wave method based on the framework of spin density functional theory. The exchange correlation potential is treated by the generalized gradient approximation of Perdew, Burke and Ernzerhof (GGA-PBE) and the modified Becke–Johnson potential mBJ-GGA-PBE form. The calculated lattice parameters, local magnetic moment and heat of formation have been calculated. The elastic constants, [Formula: see text], and other polycrystalline elastic moduli have been predicted, and the mechanical stabilities of these alloys have been theoretically confirmed. To our knowledge, the elastic constants have not yet been measured or calculated; hence, our results serve as a prediction for future study. Also, we presented results of the band structure and density of states. The electronic structure in the ferromagnetic configuration shows metallic character and that there is an exchange splitting between spin-up and spin-down bands of Ru 4d and Co3d states.

First-principles study of structural, elastic and thermodynamic properties of AuIn2

2015 ◽  
Vol 29 (34) ◽  
pp. 1550222 ◽  
Author(s):  
Hai Ying Wu ◽  
Ya Hong Chen ◽  
Chen Rong Deng ◽  
Peng Fei Yin ◽  
Hong Cao
Keyword(s):  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Elastic Constants ◽  
First Principles ◽  
Pressure Effect ◽  
Structural Parameters ◽  
Text Structure ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Theoretical Results

The structural, elastic and thermodynamic properties of [Formula: see text] in the [Formula: see text] structure under pressure have been investigated using ab initio plane wave pseudopotential method within the generalized gradient approximation. The calculated structural parameters and equation of state are in excellent agreement with the available experimental and theoretical results. The elastic constants of [Formula: see text] at ambient condition are calculated, and the bulk modulus obtained from these calculated elastic constants agrees well with the experimental data. The pressure dependence of the elastic constants, bulk modulus, shear modulus and Young’s modulus has also been investigated. The Debye temperature presents a slight increase with pressure. [Formula: see text] exhibits ductibility and low hardness characteristics, the ductibility increases while the hardness decreases with the increasing of pressure. The pressure effect on the heat capacity and thermal expansion coefficient for [Formula: see text] is much larger.

Ab initio study of structural, mechanical, thermal and electronic properties of perovskites Sr(Li,Pd)H3

2016 ◽  
Vol 30 (04) ◽  
pp. 1650003 ◽  
Author(s):  
S. Benlamari ◽  
S. Amara Korba ◽  
S. Lakel ◽  
H. Meradji ◽  
S. Ghemid ◽  
...  
Keyword(s):  
Bulk Modulus ◽  
Electronic Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Velocity Variation ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic Band

The structural, elastic, thermal and electronic properties of perovskite hydrides SrLiH3 and SrPdH3 have been investigated using the all-electron full-potential linear augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). For the exchange-correlation potential, local-density approximation (LDA) and generalized gradient approximation (GGA) have been used to calculate theoretical lattice parameters, bulk modulus, and its pressure derivative. The present results are in good agreement with available theoretical and experimental data. The three independent elastic constants [Formula: see text], [Formula: see text] and [Formula: see text] are also reported. From electronic band structure and density of states (DOSs), it is found that SrLiH3 is an insulator characterized by an indirect gap of 3.48 eV, while SrPdH3 is metallic with a calculated DOSs at Fermi energy of 0.745 states/eV-unit cell. Poisson’s ratio [Formula: see text], Young’s modulus (E), shear modulus (G), anisotropy factor (A), average sound velocities [Formula: see text] and density [Formula: see text] of these compounds are also estimated for the first time. The Debye temperature is deduced from the average sound velocity. Variation of elastic constants and bulk modulus of these compounds as a function of pressure is also reported. Pressure and thermal effects on some macroscopic properties are predicted using the quasi-harmonic Debye model.

Structural and Electronic Properties of ScC and NbC: A First Principles Study

2012 ◽  
Vol 194 ◽  
pp. 276-279 ◽  
Author(s):  
Gladys Patricia Abdel Rahim ◽  
Jairo Arbey Rodríguez
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Niobium Carbide ◽  
Full Potential ◽  
Wave Method ◽  
Generalized Gradient ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Structural And Electronic Properties ◽  
Correlation Potential

We study the structural and electronic properties of scandium carbide ScC and niobium carbide NbC in both the sodium chloride rock salt (NaCl) and wurtzite structures by means of accurate first principles total energy calculations. The calculations were performed employing the full-potential linearized plane wave method (FP-LAPW). We used the generalized gradient approximation (GGA) of Perdew Burke and Ernzerhof for the exchange and correlation potential. Volume optimization and density of states including spin (DOS) of the systems are presented.

scholarly journals First-principles study of the structural, electronic, and elastic properties of Sc2SiX (X=C, N)

2021 ◽  
Vol 67 (3 May-Jun) ◽  
pp. 500
Author(s):  
M. Mebrek ◽  
M. Berber ◽  
B. Doumi ◽  
A. Mokaddem
Keyword(s):  
Electronic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Formation Energy ◽  
Elastic Anisotropy ◽  
Surface Characteristics ◽  
Hexagonal Structure ◽  
Main Factors ◽  
The Individual ◽  
First Time

Using ab-initio calculations, we studied the structural, elastic, and electronic properties of Sc2SiX compounds with, (X=C, N). The negative formation energy and the positive cohesive energy indicate that these compounds are energetically stable and can be synthesized in normal conditions. Sc2SiC and Sc2SiN compounds are mechanically stable, estimated by the individual elastic constants. Elastic constants and modulus increase when C is substituted by N. The elastic anisotropy in Sc2SiC is high compared to Sc2SiN. Both nanolaminates are fragile in nature. Sc2SiC is more conductive than Sc2SiN. The calculated electron band structures and the density of states imply that the chemical bond in two compounds is a combination of covalent, ionic, and metallic nature. The main factors governing the electronic properties are the hybrid states Sc- 3d, Si-3p, and C -2p and the bond (p-d) stabilizes the structure. Fermi's surface characteristics have been studied for the first time, which are changed when replacing N by C. Based on the estimate of the total energy, we conclude that the replacement of C by N will lead to a stabilization of the hexagonal structure and a decrease of the metallic support.

Structural and Electronic Properties of β – CuPc: First Principles Study

2016 ◽  
Vol 675-676 ◽  
pp. 35-38
Author(s):  
Witoon Nuleg ◽  
Pitiporn Thanomngam ◽  
Kanoknan Sarasamak Phacheerak
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Energy Gap ◽  
Structural Parameters ◽  
Ambient Pressure ◽  
Generalized Gradient ◽  
Structural And Electronic Properties ◽  
Direct Band ◽  
Projector Augmented Wave ◽  
Good Agreement

Structural and electronic properties of CuPc in β structure (β - CuPc) were investigated by first principles calculations. The generalized gradient approximation (GGA) was used to describe the exchange-correlation with the projector-augmented wave (PAW) method. Under ambient pressure, the calculated structural parameters were calculated and found to be in good agreement with other experimental and theoretical values. The calculated direct band gap was found to be 0.683 eV. The results of electronic properties under various pressures were presented. To investigate the properties under pressure, β - CuPc was calculated at several reduced volumes. It was found that the energy gap decreases when the pressure increases. The behaviors of electronic properties under pressure were also discussed.

scholarly journals First-Principles Study of the Elastic Properties of Nickel Sulfide Minerals under High Pressure

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 737 ◽  
Author(s):  
Qiuyuan Zhang ◽  
Ye Tian ◽  
Shanqi Liu ◽  
Peipei Yang ◽  
Yongbing Li
Keyword(s):  
High Pressure ◽  
Elastic Wave ◽  
Wave Velocity ◽  
Elastic Constants ◽  
First Principles ◽  
Nickel Sulfide ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
Sulfide Minerals ◽  
Changing Trends

Nickel sulfide minerals, an important type of metal sulfides, are the major component of mantle sulfides. They are also one of the important windows for mantle partial melting, mantle metasomatism, and mantle fluid mineralization. The elasticity plays an important role in understanding the deformation and elastic wave propagation of minerals, and it is the key parameter for interpreting seismic wave velocity in terms of the composition of the Earth’s interior. Based on first-principles methods, the crystal structure, equation of state, elastic constants, elastic modulus, mechanical stability, elastic anisotropy, and elastic wave velocity of millerite (NiS), heazlewoodite (Ni3S2), and polydymite (Ni3S4) under high pressure are investigated. Our calculated results show that the crystal structures of these Ni sulfides are well predicted. These Ni sulfides are mechanically stable under the high pressure of the upper mantle. The elastic constants show different changing trends with increasing pressure. The bulk modulus of these Ni sulfides increases linearly with pressure, whereas shear modulus is less sensitive to pressure. The universal elastic anisotropic index AU also shows different changing trends with pressure. Furthermore, the elastic wave velocities of Ni sulfides are much lower than those of olivine and enstatite.

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