scholarly journals Investigation of the substituting effect of Se on the physical properties and performances of Cd〖Se〗_x 〖Te〗_(1-x)and Zn〖Se〗_x 〖Te〗_(1-x) materials for semiconductor radiation detectors

2021 ◽  
Vol 67 (4 Jul-Aug) ◽  
pp. 041002
Author(s):  
R. Malki ◽  
A. Tebboune ◽  
L. Ghalouci ◽  
A. Saim ◽  
A. H. Belbachir
Keyword(s):  
Density Functional ◽  
Gamma Ray ◽  
Radiation Detectors ◽  
Lattice Parameter ◽  
Full Potential ◽  
Semiconductor Detectors ◽  
The Density Functional Theory ◽  
Energy Peak ◽  
Structural And Electronic Properties ◽  
Experimental Researches

The structural and electronic properties of  and semiconductor detectors at various concentrations x = 0, 0.25, 0.5, 0.75 and 1 of Selenium (Se) were determined by using the full potential-linearized augmented plane wave (FP-LAPW) based on the density functional theory (DFT). The compositional dependence of such properties was analysed and discussed. The concentration dependence of lattice parameter and bulk modulus show nonlinearity. All the investigated alloys have a direct bandgap (Γ-Γ) which decreasesnonlinearly with increase in Se concentration. On the other hand, Geant4 simulations have been performed for studying the absolute and full-energy peak detection efficiencies and energy resolution at 1.5”×1.5” of these alloys as semiconductor detectors in the 511-1332 keV gamma-ray energy range. Ours findings are in a good agreement with the available theoretical and experimental data. We hope that our results serve as are reference for future theoretical and experimental researches.

Structural, elastic, electronic and thermoelectric properties of XPN2 (X = Li, Na): First-principles study

2019 ◽  
Vol 33 (21) ◽  
pp. 1950234
Author(s):  
T. Ghellab ◽  
H. Baaziz ◽  
Z. Charifi ◽  
K. Bouferrache ◽  
Ş Uğur ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Density Functional ◽  
Elastic Anisotropy ◽  
Three Dimensional ◽  
Lattice Parameter ◽  
Full Potential ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Electronic Parameters ◽  
Linearized Augmented Plane Wave

Based on the density functional theory (DFT) implemented by the wien2k code which uses the full potential linearized augmented plane wave plus local orbitals (APW + lo) method, we have been able to study different physical properties of X[Formula: see text]PN2 (X = Li, Na) chalcopyrite such as structural, electronic, elastic and thermoelectric properties. According to our calculations, we have found that our structural and electronic parameters, such as the lattice parameter, energy bandgap, the tetragonal ratio, the displacement of the anions, are in very good agreement with the previous experimental and theoretical results. Based on the Voigt–Reuss–Hill approximations, we were able to compute the elastic constants: the compressibility, Young’s and the shear’s moduli, the average velocity of the elastic waves, the Debye temperature and the Poisson’s coefficient of the chalcopyrite LiPN2 and NaPN2. The elastic anisotropy is estimated and further illustrated by the three-dimensional (3D) direction of Young’s and Bulk’s moduli. Finally, using the semi-classical Boltzmann theory implemented in the BolzTraP code, we calculated the transport properties such as the Seebeck coefficient, the thermal electrical conductivity and the figure of merit of these materials.

Study of Elastic Properies of Ti3Al Intermetallic Compound Using the Ab Initio Calculation

2014 ◽  
Vol 805 ◽  
pp. 690-693
Author(s):  
Carlos Alberto Soufen ◽  
Marcelo Capella de Campos ◽  
Carlos Alberto Fonzar Pintão ◽  
Momotaro Imaizumi
Keyword(s):  
Intermetallic Compound ◽  
Elastic Properties ◽  
Density Functional ◽  
Minimum Energy ◽  
Young Modulus ◽  
Lattice Parameter ◽  
Full Potential ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Equilibrium Lattice Parameter

The elastic properties of a Ti3Al intermetallic compound were studied using full potential (FP LAPW ) with the APW+lo method. The FP-LAPW is among the most accurate band structure calculations currently available and is based on the density functional theory with general gradient approximation for the exchange and correlation potential. This method provides the structural properties of the ground state as bulk modulus, equilibrium lattice parameter, and equilibrium minimum energy, and the elastic properties as shear modulus, young modulus, Zener coefficient (anisotropy), and Poisson coefficient. The calculated elastic properties are coherent with the elastic properties of the material.

FIRST-PRINCIPLE CALCULATION OF STRUCTURAL AND ELECTRONIC PROPERTIES OF ZINC-BLENDE ByAlxGa1-x-yN MATCHED TO AlN SUBSTRATE

2012 ◽  
Vol 26 (24) ◽  
pp. 1250159 ◽  
Author(s):  
LAKHDAR DJOUDI ◽  
ABDELHADI LACHEBI ◽  
BOUALEM MERABET ◽  
HAMZA ABID
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Strong Dependence ◽  
Theoretical Data ◽  
Lattice Parameter ◽  
Full Potential ◽  
Generalized Gradient ◽  
First Principle Calculation ◽  
Zinc Blende ◽  
Structural And Electronic Properties

The full-potential linearized augmented plane wave method (FP-LAPW) within density functional theory, using the generalized gradient approximation, is used to study the structural and electronic properties of zinc-blende B y Al x Ga 1-x-y N quaternary alloys that match the lattice of an AlN substrate. The range of compositions, for which the lattice of the alloy matches AlN , is determined. Our calculated band structure, density of states, electron density and lattice parameter for B y Al x Ga 1-x-y N allow to accurately evaluate the profound effect that the incorporation of small amounts of Boron have on structural and electronic properties of Al x Ga 1-x N alloys. A comparison of the ground state properties with the available experimental and theoretical data is made for the compounds related to B y Al x Ga 1-x-y N and of the Al x Ga 1-x N alloys. The results show a strong dependence of the band gap (as well as the lattice parameter) on the Boron content, which might make B y Al x Ga 1-x-y N materials promising and useful for optoelectronic applications.

Density functional study of the structural and phase transition of silver halides: LDA versus GGA calculations

2019 ◽  
Vol 08 (02) ◽  
pp. 1950006 ◽  
Author(s):  
H. Rekab Djabri ◽  
R. Yagoub ◽  
S. Bahlouli ◽  
S. Amari ◽  
S. Louhibi Fasla
Keyword(s):  
Phase Transition ◽  
Density Functional ◽  
Local Density ◽  
Structural Phase ◽  
Lattice Parameter ◽  
Functional Study ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Structural And Electronic Properties

This paper deals with the theoretical calculation of structural and electronic, properties of AgBr and AgCl compounds using density functional theory within generalized-gradient (GGA) approximation and local density approximation (LDA). We employ the full potential linear muffin-tin orbitals (FP-LMTO) as implemented in the Lmtart code. We have used to examine structure parameter in eight different structures such as in NaCl (B1), CsCl (B2), ZB (B3), NiAs (B8), PbO (B10), Wurtzite (B4), HCP (A3) [Formula: see text]Sn (A5) structures. The equilibrium lattice parameter, bulk modulus and its pressure derivative were presented for all calculated phases. The calculated ground state properties are in good agreement with available experimental and theoretical results. A pressure induced structural phase transition from NaCl (B1) to HCP (A3) phases at 37.66 and 18.11[Formula: see text]GPa for AgBr and AgCl, respectively, and from NaCl to CsCl phase in AgBr and AgCl at 90.55 and 24.4[Formula: see text]GPa, respectively, is also predicted. Furthermore, the band structures are computed. Our results are compared to other theoretical and experimental works, and excellent agreement is obtained.

scholarly journals Ab initio investigation of the electronic structure, elastic and magnetic properties of quaternary Heusler alloy Cu2MnSn1-xInx (x = 0, 0.25, 0.5, 0.75, 1)

2019 ◽  
Vol 65 (5 Sept-Oct) ◽  
pp. 468
Author(s):  
B. Benichou ◽  
H. Bouchenafa ◽  
Z. Nabi ◽  
And B. Bouabdallah
Keyword(s):  
Magnetic Properties ◽  
Heusler Alloy ◽  
Density Functional ◽  
Heusler Alloys ◽  
Theoretical Data ◽  
Lattice Parameter ◽  
Full Potential ◽  
Generalized Gradient ◽  
The Density Functional Theory ◽  
Quaternary Heusler Alloys

Structural, elastic, electronic and magnetic properties of the quaternary Heusler alloys  are calculated using the full-potential linearized augmented plane wave (FP-LAPW) method in the framework of the density functional theory (DFT) and implemented in WIEN2k code. The exchange-correlation potential is evaluated using the generalized gradient approximation (GGA) within the Perdew-Burke-Ernzerhof (PBE) parameterization. Our theoretically results provide predictions for the mixed  in which no experimental and theoretical data are currently available. The lattice parameter and bulk modulus as well the elastic constants and their related elastic moduli for  have been calculated. Also, the electronic properties including density of states and band structures indicate the metallic character for . Morever, this quaternary Heusler alloy is found to be ferromagnetic, ductile and anisotropic in nature.

Computational calculation of the relative phase of the MnN compound

2017 ◽  
Vol 11 (22) ◽  
pp. 1081-1088
Author(s):  
Miguel Jose Espitia R. ◽  
John Hernan Diaz Forero ◽  
Octavio Jose Salcedo Parra
Keyword(s):  
Density Functional ◽  
Plane Waves ◽  
External Pressure ◽  
State Density ◽  
Full Potential ◽  
Metallic Behavior ◽  
The Density Functional Theory ◽  
Computational Calculations ◽  
Structural And Electronic Properties ◽  
Manganese Nitride

In this work computational calculations ab initio were performed to determine the relative stability, the structural and electronic properties of manganese nitride MnN. The calculations were made in the structures NaCl, Zincblenda, CsCl and wurtzita; using the method increased plane waves and linearized in the full potential version (FP-LAPW), within the formalism of the density functional theory (DFT). We find that the most stable crystallization phase is Zincblende and that the compound can pass to the NaCl structure by applying an external pressure. From the DOS state density, it is found that the manganese nitride has a metallic behavior due to the Mn-d and N-p orbitals that cross the Fermi level; MnN possesses magnetic properties with a magnetic moment of 2.53 µβ/cell.

scholarly journals Ab initio calculations of structural, elastic, electronic and thermodynamic properties of the cerium filled skutterudite CeRu4P12 under the effect of pressure

2015 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mokhtar Berrahal ◽  
Mohammed Ameri ◽  
Y. Al-Douri ◽  
U. Hashim ◽  
Dinesh Varshney ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
Debye Model ◽  
Lattice Parameter ◽  
Full Potential ◽  
Generalized Gradient ◽  
Filled Skutterudite ◽  
Effect Of Pressure ◽  
Lmto Method

AbstractThe paper presents an investigation on crystalline, elastic and electronic structure in addition to the thermodynamic properties for a CeRu4P12 filled skutterudite device by using the full-potential linear muffin-tin orbital (FP-LMTO) method within the generalized gradient approximations (GGA) in the frame of density functional theory (DFT). For this purpose, the structural properties, such as the equilibrium lattice parameter, bulk modulus and pressure derivatives of the bulk modulus, were computed. By using the total energy variation as a function of strain we have determined the independent elastic constants and their pressure dependence. Additionally, the effect of pressure P and temperature T on the lattice parameters, bulk modulus, thermal expansion coefficient, Debye temperature and the heat capacity for CeRu4P12 compound were investigated taking into consideration the quasi-harmonic Debye model.

CH2O Adsorption on M (M = Li, Mg and Al) Atom Deposited ZnO Nano-Cage: DFT Study

2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Density Functional ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Formaldehyde Molecule ◽  
Electronic Configurations ◽  
Adsorption Energies ◽  
Homo Lumo

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.

The Interaction between Graphene and the SiC Substrate: Ab Initio Calculations for Polar and Nonpolar Surfaces

2016 ◽  
Vol 858 ◽  
pp. 1125-1128
Author(s):  
Ioannis Deretzis ◽  
Filippo Giannazzo ◽  
Antonino La Magna
Keyword(s):  
Density Functional Theory ◽  
Energy Spectrum ◽  
Density Functional ◽  
Low Energy ◽  
Electrical Characteristics ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Exclusive Property

Notwithstanding the graphitization of SiC under high thermal treatment can take place for all SiC surfaces, the quality of the resulting graphene as well as its structural and electrical characteristics strongly depend on the SiC face where growth has taken place. In this paper we use the density functional theory to analyze the structural and electronic properties of epitaxial graphene grown on three different SiC planes. Calculations are presented for the (6√3×6√3)R30°-reconstructed SiC(0001) surface (Si face) as well as the nonpolar SiC(11-20) and SiC(1-100) planes. We argue that the formation of a strongly-bound interface buffer layer is an exclusive property of the SiC(0001) surface. Moreover, our results indicate that nonpolar planes give rise to graphene with a nearly ideal low-energy spectrum.

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