Calculation of Structural, Electronic and Optical Properties of Double Perovskite Ca2CrNbO6

SPIN ◽  
2021 ◽  
pp. 2150012
Author(s):  
W. Benosmane ◽  
S. Benatmane ◽  
R. Bentata ◽  
W. Benstaali
Keyword(s):  
Density Functional ◽  
Double Perovskite ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
Spin Polarized ◽  
Optical Dielectric ◽  
Linearized Augmented Plane Wave

The structural electronic and magnetic properties of the double perovskite Ca2CrNbO6 in the cubic structure are investigated using the empirical full-potential linearized augmented plane wave (FP-LAPW) method within the framework of the spin-polarized density functional theory (DFT). These properties are calculated using the Generalized Gradient Approximation (GGA), [Formula: see text] and modified Becke–Johnson mBJ-GGA. In addition, the real and imaginary parts of the optical dielectric function and the reflectivity, and the refractive spectra are computed and the main features shown by their spectra are ascertained on the base of the investigation of density of states.

scholarly journals The study of structural, elastic, electronic and optical properties of CsYx I(1 − x)(Y = F, Cl, Br) using density functional theory

2017 ◽  
Vol 35 (1) ◽  
pp. 197-210 ◽  
Author(s):  
Shabeer Ahmad Mian ◽  
Muhammad Muzammil ◽  
Gul Rahman ◽  
Ejaz Ahmed
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
G Ratio ◽  
Linearized Augmented Plane Wave ◽  
Incremental Addition

AbstractThe structural, electronic, elastic and optical properties of CsYx I(1 − x)(Y = F, Cl, Br) are investigated using full potential linearized augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA). The ground state properties such as lattice constant (ao) and bulk modulus (K) have been calculated. The mechanical properties including Poisson’s ratio (σ), Young’s modulus (E), anisotropy factor (A) and shear modulus (G) were also calculated. The results of these calculations are comparable with the reported experimental and theoretical values. The ductility of CsYx I(1 − x) was analyzed using Pugh’s rule (B/G ratio) and Cauchy’s pressure (C12−C44). Our results revealed that CsF is the most ductile among the CsYxI(1 − x)(Y = F, Cl, Br) compounds. The incremental addition of lighter halogens (Yx) slightly weakens the strength of ionic bond in CsYxI(1 − x). Moreover, the optical transitions were found to be direct for binary and ternary CsYxI(1 − x). We hope that this study will be helpful in designing binary and ternary Cs halides for optoelectronic applications.

Ab-initio thermodynamic and elastic properties of AlNi and AlNi3 intermetallic compounds

2018 ◽  
Vol 32 (11) ◽  
pp. 1850129 ◽  
Author(s):  
Shahram Yalameha ◽  
Aminollah Vaez
Keyword(s):  
Intermetallic Compounds ◽  
Elastic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Wide Range ◽  
Computational Data ◽  
Linearized Augmented Plane Wave

In this paper, thermodynamic and elastic properties of the AlNi and AlNi3 were investigated using density functional theory (DFT). The full-potential linearized augmented plane-wave (APW) in the framework of the generalized gradient approximation as used as implemented in the Wien2k package. The temperature dependence of thermal expansion coefficient, bulk modulus and heat capacity in a wide range of temperature (0–1600 K) were investigated. The calculated elastic properties of the compounds show that both intermetallic compounds of AlNi and AlNi3 have surprisingly negative Poisson’s ratio (NPR). The results were compared with other experimental and computational data.

Structural, Electronic and Elastic Properties of CeTl Intermetallic Compound

2016 ◽  
Vol 28 ◽  
pp. 1-4
Author(s):  
Deepika Shrivastava ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Elastic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Cscl Type ◽  
Linearized Augmented Plane Wave

The structural, electronic and elastic properties of CeTl with CsCl-type B2 structure have been investigated using full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT) within the generalized gradient approximation (GGA) for exchange and correlation potential. The ground state properties such as lattice constant, bulk modulus and pressure derivative of bulk modulus have been calculated which are in good agreement with available experimental data. The band structure and density of state depict that 4f electrons of Ce element have dominant character in electronic conduction and are responsible for metallic character of CeTl. The charge density plot reveals that the metallic as well as ionic bonding exist between Ce and Tl atoms. The calculated elastic constants indicate that CeTl is mechanically stable in cubic B2 phase and found to be ductile in nature.

Structural and Anisotropic Elastic Properties of Hexagonal YMnO3 in Low Symmetry Determined by First-Principles Calculations

2019 ◽  
Vol 297 ◽  
pp. 120-130 ◽  
Author(s):  
Abdelhakim Chadli ◽  
Mohamed Halit ◽  
Brahim Lagoun ◽  
Ferhat Mohamedi ◽  
Said Maabed ◽  
...  
Keyword(s):  
Density Functional ◽  
Ferromagnetic State ◽  
Hexagonal Structure ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
The Density Functional Theory ◽  
Anisotropic Elastic ◽  
Linearized Augmented Plane Wave

The structural, elastic and anisotropic properties for rare earth manganites compound YMnO3 in ferromagnetic state with hexagonal structure, have been investigated using the ab initio calculations based on the density functional theory, this calculations were based on the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA). The agreement of the DFT (FP-LAPW) calculations including internal atomic relaxations, with the experimental data is very good. Other relevant quantities such as elastic constants, shear modulus, Young’s modulus, Poisson’s ratio, anisotropy factors, sound velocity, and Debye temperature have been calculated and discussed.

Electronic Structure of K2Bi8Se13

2001 ◽  
Vol 691 ◽  
Author(s):  
Daniel I Bilc ◽  
Paul Larson ◽  
S.D. Mahanti ◽  
M.G. Kanatzidis
Keyword(s):  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Ordered Structures ◽  
Augmented Plane Wave ◽  
Space Group ◽  
Β Phase ◽  
Indirect Band Gap ◽  
Linearized Augmented Plane Wave

ABSTRACTK2Bi8 Se13 belongs to a class of complex Bi-Te-Se systems which show great potential for thermoelectric performance. This compound forms in two distinct phases α-K2Bi8 Se13 (triclinic with space group P-1) and β-K2Bi8 Se13 (monoclinic with space group P 21/m). In the β-phase, there is substantial disorder at four sites in the unit cell, occupied by two K and two Bi atoms. To understand the electronic properties of these two different phases we have carried out band structure calculations within ab initio density functional theory (DFT) using full potential linearized augmented plane wave (LAPW) method. The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. Spin-orbit interaction (SOI) was incorporated using a second variational procedure. The α. phase is found to be a semiconductor with an indirect band gap of 0.47eV. For the β-phase we have chosen two different ordered structures. The system is a semi-metal for one of the structures whereas for the other, it is a narrow gap semiconductor with a gap of 0.38eV in the absence of SOI, but the gap collapses and the system becomes a semimetal with low density of states at the Fermi energy when SOI is included.

First-Principles Calculations and the Thermodynamics of Cementite

2010 ◽  
Vol 638-642 ◽  
pp. 3319-3324 ◽  
Author(s):  
Jae Hoon Jang ◽  
In Gee Kim ◽  
H.K.D.H. Bhadeshia
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Lattice Constants ◽  
Unit Cells ◽  
Linearized Augmented Plane Wave

Thermodynamic data for the substitution of silicon and manganese in cementite have been estimated using first-principles methods in order to aid the design of steels where it is necessary to control the precipitation of this phase. The need for the calculations arises from the fact that for silicon the data cannot be measured experimentally; manganese is included in the analysis to allow a comparison with its known behaviour. The calculations for Fe3C, (Fe11Si4c)C4, (Fe11Si8d)C4, (Fe11Mn4c)C4 and (Fe11Mn8d)C4 are based on the total energy all-electron full-potential linearized augmented plane-wave method within the generalized gradient approximation to density functional theory. The output includes the ground state lattice constants, atomic positions and bulk moduli. It is found that (Fe11Si4c)C4 and (Fe11Si8d)C4 have about 52 and 37 kJ greater formation energy when compared with a mole of unit cells of pure cementite, whereas the corresponding energy for (Fe11Mn4c)C4 and (Fe11Mn8d)C4 is less by about 5 kJ mol1. These results for manganese match closely with published trends and data; a similar comparison is not possible for silicon but we correctly predict that the solubility in cementite should be minimal.

Electronic Structure for Europium Chalcogenides with Modified Becke–Johnson Potential Plus an On-Site Coulomb U (mBJ+U)

SPIN ◽  
2018 ◽  
Vol 08 (04) ◽  
pp. 1850015
Author(s):  
S. Belhachi
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Full Potential ◽  
Semiconducting Materials ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Relativistic Spin ◽  
Spin Polarized ◽  
Experimental Values ◽  
Linearized Augmented Plane Wave

The full potential linearized-augmented-plane-wave (FP-LAPW) method is generalized to a case of an all-electron fully-relativistic spin-polarized self-consistent band calculation based on the relativistic spin-density functional theory and the modified Becke–Johnson potential (TB-mBJ) plus an on-site coulomb U employed for greater generation of the band gap. The results show that these materials are semiconducting materials. The indirect energy gap obtained in this calculation is 1.63[Formula: see text]eV, 1.79[Formula: see text]eV and 1.96[Formula: see text]eV for EuS, EuSe and EuTe, respectively. It is clear from the plots that LSDA[Formula: see text][Formula: see text][Formula: see text]U is a poor technique for the calculation of the band gaps of chalcogenides (EuX). The calculated results for EuX (S, Se and Te) by mBJ[Formula: see text][Formula: see text][Formula: see text]U are in good agreement with the experimental values as compared to the other calculated results.

Electronic structures, elastic, magnetic properties and half-metallicity in PtONa3 anti-perovskite

2019 ◽  
Vol 33 (29) ◽  
pp. 1950362 ◽  
Author(s):  
Oum Elkheir Youb ◽  
Zoubir Aziz ◽  
Feyza Zahira Meghoufel ◽  
Bouadjemi Boubdellah ◽  
Djoher Chenine ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Metallic Behavior ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Spin Polarized ◽  
Linearized Augmented Plane Wave

The structural, elastic, electronic and magnetic properties of the cubic [Formula: see text] anti-perovskite are investigated by means of the full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). We have used three approximations: the generalized gradient (GGA), the GGA+[Formula: see text][Formula: see text], where [Formula: see text] is on-site Coulomb interaction correction, and the modified Becke–Johnson (mBJ-GGA). The elastic constants [Formula: see text] show that our compounds are ductile and anisotropic. The results obtained for the spin-polarized band structure and the density of states show a half-metallic behavior for the compounds using the GGA, GGA+[Formula: see text][Formula: see text] and mBJ-GGA approaches. These results make [Formula: see text] a promising candidate for spintronics applications.

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.

First-principles calculations for optical investigations of PbX (X = S, Te) compounds under quantum dots diameter effect

2015 ◽  
Vol 93 (12) ◽  
pp. 1490-1494 ◽  
Author(s):  
Y. Al-Douri ◽  
H. Khachai ◽  
R. Khenata ◽  
A. Bouhemadou
Keyword(s):  
Quantum Dot ◽  
Density Functional ◽  
Energy Gap ◽  
Theoretical Data ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Linearized Augmented Plane Wave

The full potential-linearized augmented plane wave (FP-LAPW) method is implemented in WIEN2K code to calculate the indirect energy gap (Γ–X) using density functional theory. The Engel–Vosko generalized gradient approximation (EVGGA) and modified Becke–Johnson (mBJ) formalisms are used to optimize the corresponding potential for energetic transition and optical properties calculations of PbS and PbTe compounds as a function of quantum dot diameter and are used to test the validity of our model of quantum dot potential. The refractive index and optical dielectric constant are investigated to explore best applications for solar cells. The calculated results are in agreement with other experimental and theoretical data.

Sign in / Sign up

Export Citation Format

Share Document