First-principles calculations on structure and electronic properties of α-zirconium hydrogen phosphate

MRS Advances ◽  
2019 ◽  
Vol 4 (50) ◽  
pp. 2699-2707
Author(s):  
V. W. Elloh ◽  
Soni Mishra ◽  
A. Yaya ◽  
Abhishek Kumar Mishra
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Semiconductor Device ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Hydrogen Phosphate ◽  
Electronic Band ◽  
Potential Applications ◽  
Direct Band

AbstractLayered zirconium hydrogen phosphate intercalation compounds can be easily tuned, leading to potential applications in many fields, specifically by introducing them in different polymeric composites as nanofillers. Employing first-principles density functional theory based calculations, we have investigated ground state electronic structure properties of α-zirconium hydrogen phosphate (α-ZrP). We discuss the structure and electronic band structure, where projected density of states calculations have been discussed to understand the different atomic orbitals contributions to electronic bands. ZrP has numerous properties of interest for use in many semiconductor device structures, specifically, layered zirconium hydrogen phosphate has substantial promise for both optical devices and for high power electronics due to its large direct band gap. Our structural calculations suggest that layered zirconium hydrogen phosphate exhibits monoclinic structure. The calculated structural parameters and band gap are in good agreement with available experimental data.

First-principles study of electronic, optical and thermoelectric properties in cubic perovskite materials AgMO3 (M = V, Nb, Ta)

2014 ◽  
Vol 28 (10) ◽  
pp. 1450077 ◽  
Author(s):  
Asif Mahmood ◽  
Shahid M. Ramay ◽  
Hafiz Muhammad Rafique ◽  
Yousef Al-Zaghayer ◽  
Salah Ud-Din Khan
Keyword(s):  
Thermoelectric Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Perovskite Materials ◽  
Linearized Augmented Plane Wave

In this paper, first-principles calculations of structural, electronic, optical and thermoelectric properties of AgMO 3 ( M = V , Nb and Ta ) have been carried out using full potential linearized augmented plane wave plus local orbitals method ( FP - LAPW + lo ) and BoltzTraP code within the framework of density functional theory (DFT). The calculated structural parameters are found to agree well with the experimental data, while the electronic band structure indicates that AgNbO 3 and AgTaO 3 are semiconductors with indirect bandgaps of 1.60 eV and 1.64 eV, respectively, between the occupied O 2p and unoccupied d states of Nb and Ta . On the other hand, AgVO 3 is found metallic due to the overlapping behavior of states across the Fermi level. Furthermore, optical properties, such as dielectric function, absorption coefficient, optical reflectivity, refractive index and extinction coefficient of AgNbO 3 and AgTaO 3, are calculated for incident photon energy up to 50 eV. Finally, we calculate thermo power for AgNbO 3 and AgTaO 3 at fixed doping 1019 cm-3. Electron doped thermo power of AgNbO 3 shows significant increase over AgTaO 3 with temperature.

Electronic Structure and Ground State Properties of A4[Ag4O4] (A=Na, K and Rb): A First-Principles Study

2013 ◽  
Vol 665 ◽  
pp. 43-48
Author(s):  
Rajagopalan Umamaheswari ◽  
M. Yogeswari ◽  
G. Kalpana
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
First Principles Calculation ◽  
Partial Density ◽  
Electronic Band ◽  
Ground State Properties

The first-principles calculation within density functional theory is used to study in detail the electronic structure and ground state properties of alkali-metal oxoargenates A4[Ag4O4] (A= Na, K and Rb). The total energies calculated within the atomic sphere approximation (ASA) were used to determine the ground state properties such as equilibrium lattice parameter, c/a ratio, bulk modulus and cohesive energy. The theoretically calculated equilibrium lattice constants values are in well agreement with the available experimental values. The electronic band structures, total and partial density of states are calculated. The result of electronic band structure shows that the KAgO and RbAgO are direct band gap semiconductors with their gap lying between the Γ-Γ points, whereas NaAgO is found to be an indirect band gap semiconductor with its gap lying between Z-Γ points.

scholarly journals The structural, elastic, electronic and optical properties of MgCu under pressure: A first-principles study

2016 ◽  
Vol 30 (27) ◽  
pp. 1650199 ◽  
Author(s):  
Md. Afjalur Rahman ◽  
Md. Zahidur Rahaman ◽  
Md. Atikur Rahman
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Normal Pressure ◽  
Type Structure ◽  
Ultraviolet Region ◽  
Electronic Band ◽  
Electronic And Optical Properties

The effect of pressure on the structural, elastic and electronic properties of the intermetallic compound MgCu with a CsCl-type structure have been investigated using ab initio technique. The optical properties have been studied under normal pressure. We have carried out the plane-wave pseudopotential approach within the framework of the first-principles density functional theory (DFT) implemented within the CASTEP code. The calculated structural parameters show a good agreement with the experimental and other theoretical results. The most important elastic properties including the bulk modulus [Formula: see text], shear modulus [Formula: see text], Young’s modulus [Formula: see text] and Poisson’s ratio [Formula: see text] of the cubic-type structure MgCu are determined under pressure by using the Voigt–Reuss–Hill (VRH) averaging scheme. The results show that the MgCu intermetallic becomes unstable under pressure more than 15 GPa. The study of Cauchy pressure and Pugh’s ratio exhibit brittle nature of MgCu at ambient condition and the compound is transformed into ductile nature with the increase of pressure. For the first time we have investigated the electronic and optical properties of MgCu. The electronic band structure reveals metallic conductivity and the major contribution comes from Cu-[Formula: see text] states. Reflectivity spectrum shows that the reflectivity is high in the ultraviolet region up to 72 eV.

Structural, Optoelectronic and Thermoelectric Properties of Ternary CaBe2X2 (X = N, P, As, Sb, Bi) Compounds

2018 ◽  
Vol 73 (10) ◽  
pp. 965-973 ◽  
Author(s):  
Abdul Ahad Khan ◽  
Aziz Ur Rehman ◽  
A. Laref ◽  
Masood Yousaf ◽  
G. Murtaza
Keyword(s):  
Band Gap ◽  
Thermoelectric Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Infrared Region ◽  
Ultraviolet Region ◽  
Thermo Electric ◽  
Electronic Band ◽  
Electron Charge Density

AbstractThe structural, electronic, optical and thermoelectric properties of ternary CaBe2X2 (X = N, P, As, Sb and Bi) have been investigated comprehensively for the first time using density functional theory. All the compounds are optimized to obtain their ground states. Computed structural parameters agree to the available experimental results. Electronic band structure calculations reveal the semiconducting nature of the compounds, while bang gap decreases by changing the anion X from N to Bi the band gap decreases. In the valence band, major contribution is due to X-p state, while in conduction band (CB) the major contribution is mainly due to the Ca-d state. Furthermore, electron charge density plots reveal ionic bonding character with small covalent bonding. Optical properties are calculated in detail. Static value of refractive index shows inverse variation with band gap. The refractive indices of these compounds are high in the infrared region and gradually decreased in the visible and ultraviolet region. The thermoelectric properties are studied using Boltzmann statistics through BoltzTraP code. High optical conductivity peaks and figure of merits (ZT) for compounds reveal that they are good candidates for the optoelectronics and thermo-electric devices.

FIRST PRINCIPLE CALCULATION OF ELECTRONIC BAND STRUCTURE AND OPTICAL PROPERTIES OF KIO3

2009 ◽  
Vol 23 (10) ◽  
pp. 2405-2412
Author(s):  
HARUN AKKUS ◽  
BAHATTIN ERDINC
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Functional Methods ◽  
A Value ◽  
Direct Band

The electronic band structure and optical properties of the ferroelectric single crystal KIO 3 have been investigated using the density functional methods. The calculated band structure for KIO 3 evidences that the crystal has a direct band gap with a value of 2.83 eV. The structural optimization has been performed. The real and imaginary parts of dielectric function, energy-loss function for volume and surface, and refractive index are calculated along the crystallographic axes.

scholarly journals DFT calculations of the structure and stability of copper clusters on MoS2

2020 ◽  
Vol 11 ◽  
pp. 391-406
Author(s):  
Cara-Lena Nies ◽  
Michael Nolan
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Noble Metals ◽  
Semiconductor Device ◽  
2D Materials ◽  
Single Atom ◽  
Copper Binding ◽  
Adsorption Sites ◽  
Potential Applications ◽  
Low Dimensional

Layered materials, such as MoS2, are being intensely studied due to their interesting properties and wide variety of potential applications. These materials are also interesting as supports for low-dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal structures and MoS2 monolayers is therefore of significant importance and first-principles simulations can probe aspects of this interaction not easily accessible to experiment. Previous theoretical studies have focused particularly on the adsorption of a range of metallic elements, including first-row transition metals, as well as Ag and Au. However, most studies have examined single-atom adsorption or adsorbed nanoparticles of noble metals. This means there is a knowledge gap in terms of thin film nucleation on 2D materials. To begin addressing this issue, we present in this paper a first-principles density functional theory (DFT) study of the adsorption of small Cu n (n = 1–4) structures on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms adsorb atop the S atoms. Stability is driven by the number of Cu–Cu interactions and the distance between adsorption sites, with no obvious preference towards 2D or 3D structures. The introduction of a single S vacancy in the monolayer enhances the copper binding energy, although some Cu n nanoclusters are actually unstable. The effect of the vacancy is localised around the vacancy site. Finally, on both the pristine and the defective MoS2 monolayer, the density-of-states analysis shows that the adsorption of Cu introduces new electronic states as a result of partial Cu oxidation, but the metallic character of Cu nanoclusters is preserved.

scholarly journals Structural, Electronic and Vibrational Properties of YAl3(BO3)4

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 545 ◽  
Author(s):  
Aleksandr S. Oreshonkov ◽  
Evgenii M. Roginskii ◽  
Nikolai P. Shestakov ◽  
Irina A. Gudim ◽  
Vladislav L. Temerov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Band Gap ◽  
Density Functional ◽  
Dielectric Material ◽  
Electronic Band Structure ◽  
Vibrational Properties ◽  
Electronic Band ◽  
Functional Theory ◽  
Dynamical Properties ◽  
Indirect Band Gap

The crystal structure of YAl3(BO3)4 is obtained by Rietveld refinement analysis in the present study. The dynamical properties are studied both theoretically and experimentally. The experimental Raman and Infrared spectra are interpreted using the results of ab initio calculations within density functional theory. The phonon band gap in the Infrared spectrum is observed in both trigonal and hypothetical monoclinic structures of YAl3(BO3)4. The electronic band structure is studied theoretically, and the value of the band gap is obtained. It was found that the YAl3(BO3)4 is an indirect band gap dielectric material.

FIRST-PRINCIPLES STUDIES ON THE ELECTRONIC STRUCTURE OF LuPd2Si2

2009 ◽  
Vol 23 (32) ◽  
pp. 5929-5934 ◽  
Author(s):  
T. JEONG
Keyword(s):  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Spin Orbit Coupling ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Scheme

The electronic band structure of LuPd 2 Si 2 was studied based on the density functional theory within local density approximation and fully relativistic schemes. The Lu 4f states are completely filled and have flat bands around -5.0 eV. The fully relativistic band structure scheme shows that spin–orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplet.

Electronic Band Structure of Cubic Silicon Carbide Nanowires

2008 ◽  
Vol 600-603 ◽  
pp. 575-578 ◽  
Author(s):  
A. Miranda ◽  
A. Estrella Ramos ◽  
M. Cruz Irisson
Keyword(s):  
Silicon Carbide ◽  
Band Structure ◽  
Band Gap ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Thickness Variation ◽  
Hydrogen Atoms ◽  
Electronic Band ◽  
Cubic Silicon Carbide

In this work, the effects of the diameter and morphology on the electronic band structure of hydrogenated cubic silicon carbide (b-SiC) nanowires is studied by using a semiempirical sp3s* tight-binding (TB) approach applied to the supercell model, where the Si- and C-dangling bonds on the surface are passivated by hydrogen atoms. Moreover, TB results (for the bulk) are compared with density functional calculations in the local density approximation. The results show that though surface morphology modifies the band gap, the change is more systematic with the thickness variation. As expected, hydrogen saturation induces a broadening of the band gap energy because of the quantum confinement effect.

Theoretical Investigation on Electronic Properties of ZnO Crystals Using DFT-Based Calculation Method

2015 ◽  
Vol 1112 ◽  
pp. 41-44 ◽  
Author(s):  
Yudi Darma ◽  
Freddy Giovanni Setiawan ◽  
Muhammad Aziz Majidi ◽  
Andrivo Rusydi
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Valence Band Maximum ◽  
Band Gaps ◽  
Generalized Gradient ◽  
Strong Electron ◽  
Electronic Band ◽  
Rocksalt Structure

We study the electronic band structure and density of states (DOS) on ZnO material in various crystal structures : wurtzite (W), zincblende (ZB), and rocksalt (RS) phases. Calculations are based on Density Functional Theory (DFT) with Generalized Gradient Approximation (GGA) for exchange-correlation functional and Hubbard correction to consider the strong electron correlations in 3d orbitals. After structural optimization, GGA results show that wurtzite and zincblende structures have a direct band gap of 0.749 eV and 0.637 eV, respectively, whereas rocksalt structure has an indirect band gap of 0.817 eV. Symmetrical shape of total DOS for spin up and spin down electrons indicates a zero total magnetic moment. For all ZnO structures, the upper valence band is formed by hybridization among O 2p and Zn 3d orbitals, while lower valence and conduction band are primarily filled by O 2s and Zn 4s, respectively. The GGA+U approach is found to improve the calculated band gaps and correct the position of Zn 3d state below Valence Band Maximum (VBM). From GGA+U, the band gaps for W-ZnO, ZB-ZnO, and RS-ZnO are 1.12 eV, 1.00 eV, and 1.11 eV, respectively.

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