FIRST PRINCIPLES STUDY OF STRUCTURAL, ELECTRONIC AND OPTICAL PROPERTIES OF HALF-HEUSLER ALLOYS LIMGN, NaMGN AND KMGN

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Nor Safikah Masuri ◽  
R. Ahmed ◽  
A. Shaari ◽  
Bakhtiar Ul Haq ◽  
Mazmira Mohamad ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Structural Parameters ◽  
Heusler Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Previous Theory ◽  
Augmented Plane Wave ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

In this study, we performed our calculations using the full-potential linearized-augmented plane wave (FP-LAPW) method as implemented in the WIEN2k code based on DFT. The generalized gradient functional with the Wu-Cohen (WC) parameterization was used to evaluate the structural, electronic, optical and thermoelectric properties of the materials under this study. We have calculated the structural parameters and our obtained results are in good agreement with available experimental and previous theory calculations. The density of states and band structure figures have been calculated and analyzed. The optical properties that covered by dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity and energy-loss function have been calculated and analyzed in a range energy from 0eV to 30eV.

First principles study of electronic and optical properties of InAs

Open Physics ◽  
2009 ◽  
Vol 7 (4) ◽  
Author(s):  
Zhenbao Feng ◽  
Haiquan Hu ◽  
Shouxin Cui ◽  
Wenjun Wang ◽  
Canyun Lu
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Optical Absorption Coefficient ◽  
Full Potential ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Augmented Plane Wave ◽  
Electronic And Optical Properties ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

AbstractThe electronic and optical properties of InAs in core-level spectra are calculated using the full-potential linearized augmented plane wave plus local orbitials (FP-LAPW +lo) method. The real and imaginary parts of the dielectric function ε(ω), the optical absorption coefficient I(ω), the reflectivity R(ω), the refractive index n(ω), and the extinction coefficient k(ω)are calculated. All these values are in good agreement with the experimental data. The effect of spin-orbit coupling on optical properties is also investigated and found to be quite small.

Band Structure and Optical Properties of CuInSe2

2014 ◽  
Vol 894 ◽  
pp. 254-258
Author(s):  
Rong Zhen Chen ◽  
Clas Persson
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Coupling Effect ◽  
Full Potential ◽  
Spin Orbit Coupling ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

In this work, the electronic structure and dielectric function of chalcopyrite CuInSe2 are presented. The results are based on the full-potential linearized augmented plane wave (FPLAPW) method using the generalized gradient approximation (GGA) plus an onsite Coulomb interaction U of the Cu d states. The dielectric constant, absorption coefficient and refractive index are explored by means of optical response. The spin-orbit coupling effect is considered for the calculations of electronic structure and optical properties. We find that the results based on our calculation method have good agreement compared with experimental and other earlier simulations results.

First-principles calculations of electronic and magnetic properties of XMn2Y2 (X = Ca, Sr; Y = Sb, Bi) compounds

2019 ◽  
Vol 33 (18) ◽  
pp. 1950199
Author(s):  
Zeshan Zada ◽  
A. Laref ◽  
G. Murtaza ◽  
Aurang Zeb ◽  
A. Yar
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Full Potential ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Spin Configuration ◽  
Augmented Plane Wave ◽  
Electronic And Magnetic Properties ◽  
Magnetic Stability ◽  
Linearized Augmented Plane Wave

We have examined the magnetic stability; antiferromagnetic (AFM) ordering; electronic and magnetic properties of composition XMn2Y2 (X = Ca, Sr; Y = Sb, Bi) using framework of full-potential linearized augmented plane wave (FP-LAPW) method within generalized gradient (PBE-GGA) approximations in AFM phase. We have specified that AFM state is most suitable for these compounds as compared to other configurations at their relaxed lattice parameters. An AFM spin configuration of Mn atoms is shown to be impressive state for these compounds. Based on its electronic properties, these compounds have a metallic nature in Paramagnetic (PM) but in AFM phase it shows different nature from PM phase. From a suitable phase, it has been cleared that both Mn atoms well-adjusted antiferromagnetically.

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.

scholarly journals Модельный подход к описанию свойств графана: аналитические результаты

2020 ◽  
Vol 62 (12) ◽  
pp. 2188
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Mechanical Properties ◽  
Local Density ◽  
Hexagonal Structure ◽  
Full Potential ◽  
Dirac Cone ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Experimental Works ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

Since its discovery in 2004, graphene has attracted the intention of several researchers in the world because of its fascinating electronic and mechanical properties. Various theoretical and experimental works have been devoted to this material. In this paper, we used a full-potential linearized augmented plane-wave (FP-LAPW) method to investigate the structural, electronic, and mechanical properties of graphene in hexagonal structure within local density and generalized gradient approximations (LDA and GGA). Our results are found in good agreement with other theoretical and experimental contributions. Using a modified Becke--Johnsone GGA approximation, we have also confirmed that graphene is a zero-gap semiconductor with the presence of a Dirac cone. In our contribution, we have also calculated the elastic constants, the Young's modulus and Poisson's ratio of graphene that are found in good agreement with the results published in the literature.

Theoretical approach to explore structural, electronic, magnetic, elastic and thermal characteristics of Heusler alloys CoYTiZ (Z = Al, Ga, Si, Ge)

2021 ◽  
Vol 35 (24) ◽  
Author(s):  
M. Shakil ◽  
Seemab Fatima Tufail ◽  
Muhammad Isa Khan ◽  
Saba Aziz ◽  
S. S. A. Gillani ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Heusler Alloys ◽  
Geometry Optimization ◽  
Thermal Characteristics ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Quaternary Heusler Alloys ◽  
Ferro Magnetic ◽  
Linearized Augmented Plane Wave

In this study, structural, electronic, magnetic, elastic and thermal properties of Co-based Quaternary Heusler alloys (QHAs) CoYTiZ ([Formula: see text], Ga, Si, Ge) have been investigated by Wien2k code. The calculations have been performed using full-potential linearized augmented plane wave (FP-LAPW) method. Generalized Gradient Approximation (GGA) method has been adopted. Structural properties have been explored for three different Wyckoff positions. From the geometry optimization calculations, it is concluded that all these alloys are stable in Type-III crystal structure. Moreover, magnetic phase optimization revealed ferro-magnetic (FM) phase as stable one. Results of electronic properties have shown metallic character for CoYTiAl, CoYTiGa, CoYTiGe while nearly half metal (HM) character for CoYTiSi. Magnetic moment obeys Slater Pauling rule (SP) for these alloys. To check out the mechanical stability, elastic properties have been investigated. Elastic parameters have shown the ductile nature of these alloys. The values for melting temperature ([Formula: see text] have confirmed the thermal stability of the studied alloys.

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.

Optical Properties of Si Quantum Dot Potential under Pressure Effect

2012 ◽  
Vol 545 ◽  
pp. 32-37
Author(s):  
Y. Al-Douri
Keyword(s):  
Optical Properties ◽  
Quantum Dot ◽  
Energy Gap ◽  
Pressure Effect ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Si Quantum Dot ◽  
Linearized Augmented Plane Wave ◽  
Transverse Effective Charge

Further study of the quantum dot potential under hydrostatic pressure for Si is presented. This potential has been calculated by means of our recent empirical model. The indirect energy gap (Γ-X) is calculated using the full potential-linearized augmented plane wave (FP-LAPW) method. The Engel-Vosko generalized gradient approximation (EV-GGA) formalism is used to optimize the corresponding potential for energetic transition and optical properties calculations of Si. The refractive index and transverse effective charge are predicted under pressure effect. The pressure effect is used to test the validity of our model. The results are compared with others and showed reasonable agreement.

scholarly journals First-principles calculations of antimony sulphide Sb2S3

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Afiq Radzwan ◽  
Rashid Ahmed ◽  
Amiruddin Shaari ◽  
Abdullahi Lawal ◽  
Ying Xuan Ng
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Metal Chalcogenides ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Linearized Augmented Plane Wave

The structural, electronic and optical  properties of Sb2S3 have been investigated  using full-potential linearized augmented plane wave method within density functional theory (DFT) framework, treating exchange-correlation potential with Engel-Vosko generalized gradient approximation (EV-GGA). Electronic properties calculations were performed  with and without taken into account the effects of spin-orbit coupling (SOC) . From our results we found that structural properties,density of states and band structure are in good agreement with experimental results.The effects of SOC and relativistic on electronic properties were found to be negligible. However, optical properties, namely, imaginary and real parts of dielectric function, reflectivity, absorption coefficient, refractive index, extinction coefficient and energy loss function were calculated and analyized.Optical gap of 1.61 eV proves that Sb2S3 metal chalcogenides is a promising material for solar cell device.

scholarly journals Structural, electronic, optical properties and first-principles calculations of Sr1-xCaxWO4 ceramics

2019 ◽  
Vol 9 (3) ◽  
pp. 199-211
Author(s):  
Mohammed Ait Haddouch ◽  
Youssef Tamraoui ◽  
Fatima-Ezzahra Mirinioui ◽  
Youssef Aharbil ◽  
Hicham Labrim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Solid State Reaction Method ◽  
Full Potential ◽  
X Ray Diffraction ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Linearized Augmented Plane Wave

A series of strontium calcium tungstates Sr1-xCaxWO4 powders with (x = 0; 0.25; 0.5; 0.75 and 1.0) were prepared by solid-state reaction method and analyzed by X-ray diffraction (XRD). All these compositions possess a tetragonal scheelite structure with I41/a space group. Raman active vibrational modes in the range from 20 to 1000 cm-1 of the series Sr1-xCaxWO4 with tetragonal structure exhibit 13 modes in arrangement with the Group theory analysis of structural Raman-active modes. The optical properties were investigated using the diffuse reflectance UV–visible absorbance spectrum. Based on Density Functional Theory (DFT) and using full Potential-linearized Augmented Plane Wave (FP-LAPW) method with the Local Density Approximation and the Generalized Gradient Approximation (GGA), implemented in the Wien2k package, we have investigated electronic and optical properties of all the compositions. The results indicate a decrease in the values of the optical direct bandgap (from 4.29 to 3.87 eV) with the increase of Ca into SrWO4 lattice, which is in good agreement with our experimental results.

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