scholarly journals Elastic, mechanical and thermodynamic properties of zinc blende III-X (X= As, Sb): ab-initio calculations

2019 ◽  
Vol 4 (1) ◽  
pp. 23
Author(s):  
Miloud IBRIR
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Local Density ◽  
Potential Method ◽  
Ground State Structure ◽  
Full Potential ◽  
Lattice Constants ◽  
Calculated Stress ◽  
Linear Fit

In this work, density functional theory plane-wave full potential method, with local density approximation (LDA) are used to investigate the structural, mechanical and thermodynamic properties of of zincblende III-X ( X= As, Sb) compends. Comparison of the calculated equilibrium lattice constants and experimental data shows very good agreement. The elastic constants were determined from a linear fit of the calculated stress-strain function according to Hooke’s law. From the elastic constants, the bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio σ, anisotropy factor A, the ratio B/G and the hardness parameter H for zincblende III-X ( X= As, Sb) compound are obtained. Our calculated elastic constants indicate that the ground state structure of III-X ( X= As, Sb) is mechanically stable. The sound velocities and Debye temperature are also predicted from elastic constants.

Theoretical study of phonon dispersion, elastic, mechanical and thermodynamic properties of barium chalcogenides

2018 ◽  
Vol 32 (08) ◽  
pp. 1850092 ◽  
Author(s):  
A. A. Musari ◽  
S. A. Orukombo
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Potential Method ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Lattice Constants ◽  
Linear Fit ◽  
Specific Heat Capacities

Barium chalcogenides are known for their high-technological importance and great scientific interest. Detailed studies of their elastic, mechanical, dynamical and thermodynamic properties were carried out using density functional theory and plane-wave pseudo potential method within the generalized gradient approximation. The optimized lattice constants were in good agreement when compared with experimental data. The independent elastic constants, calculated from a linear fit of the computed stress–strain function, were used to determine the Young’s modulus (E), bulk modulus (B), shear modulus (G), Poisson’s ratio ([Formula: see text]) and Zener’s anisotropy factor (A). Also, the Debye temperature and sound velocities for barium chalcogenides were estimated from the three independent elastic constants. The calculations of phonon dispersion showed that there are no negative frequencies throughout the Brillouin zone. Hence barium chalcogenides have dynamically stable NaCl-type crystal structure. Finally, their thermodynamic properties were calculated in the temperature range of 0–1000 K and their constant-volume specific heat capacities at room-temperature were reported.

Structural, electronic and elastic properties of the B2-ScM (M =Au, Hg and Tl) intermetallic compounds: Ab initio calculations

2015 ◽  
Vol 04 (04) ◽  
pp. 1550020
Author(s):  
Ahmad A. Mousa ◽  
Jamil M. Khalifeh
Keyword(s):  
Mechanical Properties ◽  
Bulk Modulus ◽  
Intermetallic Compounds ◽  
Elastic Constants ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic Band

Structural, electronic, elastic and mechanical properties of ScM (M[Formula: see text][Formula: see text][Formula: see text]Au, Hg and Tl) intermetallic compounds are studied using the full potential-linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT), within the generalized gradient approximation (GGA) and the local density approximation (LDA) to the exchange-correlation approximation energy as implemented in the Wien2k code. The ground state properties including lattice parameters, bulk modulus and elastic constants were all computed and compared with the available previous theoretical and experimental results. The lattice constant was found to increase in contrast to the bulk modulus which was found to decrease with every substitution of the cation (M) starting from Au till Tl in ScM. Both the electronic band structure and density-of-states (DOS) calculations show that these compounds possess metallic properties. The calculated elastic constants ([Formula: see text], [Formula: see text] and [Formula: see text] confirmed the elastic stability of the ScM compounds in the B2-phase. The mechanical properties and ductile behaviors of these compounds are also predicted based on the calculated elastic constants.

Investigation of the structural, electronic, elastic and thermodynamic properties of Curium Monopnictides: An ab initio study

2017 ◽  
Vol 31 (30) ◽  
pp. 1750226 ◽  
Author(s):  
H. Baaziz ◽  
Dj. Guendouz ◽  
Z. Charifi ◽  
S. Akbudak ◽  
G. Uğur ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Structural Phase ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Spin Polarized

The structural, electronic, elastic and thermodynamic properties of Curium Monopnictides CmX (X = N, P, As, Sb and Bi) are investigated using first-principles calculations based on the density functional theory (DFT) and full potential linearized augmented plane wave (FP-LAPW) method under ambient condition and high pressure. The exchange-correlation term is treated using two approximations spin-polarized local density approximation (LSDA) and spin-polarized generalized gradient approximation generalized (GGA). The structural parameters such as the equilibrium lattice parameters, bulk modulus and the total energies are calculated in two phases: namely NaCl (B1) and CsCl (B2). The obtained results are compared with the previous theoretical and experimental results. A structural phase transition from B1 phase to B2 phase for Curium pnictides has been obtained. The highest transition pressure is 122 GPa for CmN and the lowest one is 10.0 GPa for CmBi compound. The electronic properties show that these materials exhibit half-metallic behavior in both phases. The magnetic moment is found to be around 7.0 [Formula: see text]B. The mechanical properties of CmX (X = N, P, As, Sb and Bi) are predicted from the calculated elastic constants. Our calculated results are in good agreement with the theoretical results in literature. The effect of pressure and temperature on the thermodynamic properties like the cell volume, bulk modulus and the specific heats C[Formula: see text] and C[Formula: see text], the entropy [Formula: see text] and the Grüneisen parameter [Formula: see text] have been foreseen at expanded pressure and temperature ranges.

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.

Mechanical, electronic and thermodynamic properties of full Heusler compounds Fe2VX(X = Al, Ga)

2015 ◽  
Vol 29 (31) ◽  
pp. 1550229 ◽  
Author(s):  
M. Khalfa ◽  
H. Khachai ◽  
F. Chiker ◽  
N. Baki ◽  
K. Bougherara ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Local Density ◽  
Theoretical Data ◽  
Debye Model ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Lattice Constants ◽  
Full Heusler ◽  
Good Agreement

The electronic structure, mechanical and thermodynamic properties of Fe2VX, (with X = Al and Ga), have been studied self consistently by employing state-of-the-art full-potential linearized approach of augmented plane wave plus local orbitals (FP-LAPW + lo) method. The exchange-correlation potential is treated with the local density and generalized gradient approximations (LDA and GGA). Our predicted ground state properties such as lattice constants, bulk modulus and elastic constants appear more accurate when we employed the GGA rather than the LDA, and these results are in very good agreement with the available experimental and theoretical data. Further, thermodynamic properties of Fe2VAl and Fe2VGa are predicted with pressure and temperature in the ranges of 0–40 GPa and 0–1500 K using the quasi-harmonic Debye model. We have obtained successfully the variations of the heat capacities, primitive cell volume and volume expansion coefficient.

scholarly journals Half-metallic characteristic in the new full-Heusler SrYO-=SUB=-2-=/SUB=- (Y = Sc, Ti, V and Cr) -=SUP=-*-=/SUP=-

2019 ◽  
Vol 61 (1) ◽  
pp. 41
Author(s):  
N. Nazemi ◽  
F. Ahmadian
Keyword(s):  
Density Functional ◽  
Ground State Structure ◽  
Full Potential ◽  
Half Metallicity ◽  
Half Metallic ◽  
Plane Wave Method ◽  
Lattice Constants ◽  
Wide Range ◽  
Magnetic Metal ◽  
Linearized Augmented Plane Wave

AbstractHalf-metallic properties of SrYO_2 (Y = Sc, Ti, V, and Cr) full-Hensler compounds were studied using full-potential linearized augmented plane wave method based on density functional theory. The negative formation energies of SrYO_2 (Y = Sc, Ti, V, and Cr) alloys confirmed that they can be synthesized experimentally. Total energy calculations showed that AlCu_2Mn-type structure was the ground state structure in all compounds. In both structures, SrYO_2 (Y = Ti, V, and Cr) alloys were half-metallic ferrromagnets, while SrScO_2 was a non- magnetic metal. The origin of half-metallicity was verified for SrCrO_2. SrYO_2 (Y = Ti, V, and Cr) alloys in both structures were half-metals in a wide range of lattice constants indicating that they are quite robust against hydrostatic strains. The magnetization of SrYO_2 (Y = Ti, V, and Cr) alloys was mainly originated from the 3 d electrons of Y (= Ti, V, and Cr) atoms and followed the Slater–Pauling rule: M _tot = Z _tot – 12. Generally, It is expected that SrYO_2 (Y = Ti, V, and Cr) alloys are promising and interesting candidates in the future spintronic field.

STRUCTURAL, ELECTRONIC, OPTICAL AND THERMODYNAMIC PROPERTIES OF PbS, PbSe AND THEIR TERNARY ALLOY PbS1-xSex

2011 ◽  
Vol 25 (07) ◽  
pp. 473-486 ◽  
Author(s):  
M. LABIDI ◽  
H. MERADJI ◽  
S. GHEMID ◽  
S. LABIDI ◽  
F. EL HAJ HASSAN
Keyword(s):  
Thermodynamic Properties ◽  
Density Functional ◽  
Enthalpy Of Mixing ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Ordered Structures ◽  
Augmented Plane Wave ◽  
Lattice Constants ◽  
Linearized Augmented Plane Wave

On the basis of ab initio calculations employing density functional theory (DFT), we investigate the structural, electronic, optical and thermodynamic properties of two binaries: PbS and PbSe in rock-salt structures. In addition, several compositions with various ordered structures of PbS 1-x Se x alloys were studied. The calculations were performed using the full potential linearized augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA). Various quantities, such as equilibrium lattice constants, bulk modulus, band structures and refractive index for all Se -concentrations are presented. The microscopic origins of the gap bowing were explained by using the approach of Zunger and coworkers. On the other hand, the thermodynamic stability of these alloys was investigated by calculating the excess enthalpy of mixing ΔHm as well as the phase diagram.

scholarly journals Band Gap Engineering of Cd1-xBexSe Alloys

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Djillali Bensaid ◽  
Mohammed Ameri ◽  
Nadia Benseddik ◽  
Ali Mir ◽  
Nour Eddine Bouzouira ◽  
...  
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Full Potential ◽  
Electronic Band ◽  
Band Gap Engineering ◽  
Lattice Constants ◽  
Optical Dielectric Constant ◽  
Lmto Method ◽  
Optical Dielectric

The structural and electronic properties of the ternary Cd1-xBexSe alloys have been calculated using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory within local density approximation (LDA). The calculated equilibrium lattice constants and bulk moduli are compared with previous results. The concentration dependence of the electronic band structure and the direct and indirect band gaps are investigated. Moreover, the refractive index and the optical dielectric constant for Cd1-xBexSe are studied. The thermodynamic stability of the alloys of interest is investigated by means of the miscibility. This is the first quantitative theoretical prediction to investigate the effective masses, optical and thermodynamic properties for Cd1-xBexSe alloy, and still awaits experimental.

Theoretical investigations of the structural, electronic and optical properties of Hg1−xCdxS alloys

2016 ◽  
Vol 30 (11) ◽  
pp. 1650173 ◽  
Author(s):  
S. Al-Rajoub ◽  
B. Hamad
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Ternary Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Electronic And Optical Properties ◽  
Lattice Constants ◽  
Theoretical Investigations

The structural, electronic and optical properties of mercury cadmium sulfide (Hg[Formula: see text]Cd[Formula: see text]S) alloys with [Formula: see text] = 0.0, 0.25, 0.5, 0.75 are studied using density functional theory (DFT) within full-potential linearized augmented plane wave (FPLAPW) method. We used the local density approximation (LDA), the generalized gradient approximation (GGA), Hubbard-corrected functionals (GGA/LDA[Formula: see text]+[Formula: see text][Formula: see text]) and the modified Becke–Johnson (LDA/GGA)-mjb hybrid potentials to treat the exchange-correlation functional [Formula: see text]. We found that LDA functional predicts better lattice constants than GGA functional. Mercury sulfide (HgS) binary alloy was found to exhibit a semi-metallic behavior using all functional with an inverted band gap close to the experimental value. However, the hybrid functionals were more successful than LDA and GGA functionals to predict the correct electronic structure of Hg[Formula: see text]Cd[Formula: see text]S ternary alloys. The results of the electronic and optical band gaps are consistent for Hg[Formula: see text]Cd[Formula: see text]S ternary alloys.

STRUCTURAL PROPERTIES OF III-NITRIDE BINARY COMPOUNDS: A COMPREHENSIVE STUDY

2009 ◽  
Vol 23 (08) ◽  
pp. 1111-1127
Author(s):  
RASHID AHMED ◽  
FAZAL-E-ALEEM ◽  
HARIS RASHID ◽  
H. AKBARZADEH ◽  
S. JAVAD HASHEMIFAR
Keyword(s):  
Structural Properties ◽  
Rock Salt ◽  
Density Functional ◽  
Correlation Energy ◽  
Local Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Lattice Constants ◽  
Binary Compounds

Very little information is available about the structural properties of III-nitride binary compounds in the rock-salt phase. We report/review a comprehensive theoretical study of structural properties of these compounds in rock-salt, zinc-blende and wurtzite phases. Calculations have been made using full-potential linearized augmented plane wave plus local orbitals (FP-L(APW+lo)) method as embodied in WIEN2k code framed within density functional theory (DFT). In this approach of calculations, local density approximation (LDA) [J. P. Perdew and Y. Wang, Phys. Rev. B45 (1992) 13244] and generalized gradient approximation (GGA) [J. P. Perdew, K. Burke and M. Ernzerhof, Phys. Rev. Lett.72 (1996) 3865] have been used for exchange-correlation energy and corresponding potential. Calculated results for lattice constants, bulk modulus, its pressure derivative and cohesive energy of these compounds are consistent with the experimental results. Following these calculations, besides many new results for the rock-salt and other phases, a comprehensive review of the structural properties emerges. We also list some peculiar features of these compounds.

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