Electronic band structure of YBa2Cu3O7 and YBa2Cu3O6 by density functional pseudopotential method

1992 ◽  
Vol 195 (3-4) ◽  
pp. 230-238 ◽  
Author(s):  
Masahiko Hirao ◽  
Tsuyoshi Uda ◽  
Yoshimasa Murayama
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Pseudopotential Method ◽  
Electronic Band

Ab initio calculation on the Optical Properties of AA- Stacked two dimensional Graphene, Silicene, Germanene, and Stanene

2018 ◽  
Vol 1 (1) ◽  
pp. 46-50
Author(s):  
Rita John ◽  
Benita Merlin
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Complex Refractive Index ◽  
Single Layer ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Wide Range ◽  
Optical Region

In this study, we have analyzed the electronic band structure and optical properties of AA-stacked bilayer graphene and its 2D analogues and compared the results with single layers. The calculations have been done using Density Functional Theory with Generalized Gradient Approximation as exchange correlation potential as in CASTEP. The study on electronic band structure shows the splitting of valence and conduction bands. A band gap of 0.342eV in graphene and an infinitesimally small gap in other 2D materials are generated. Similar to a single layer, AA-stacked bilayer materials also exhibit excellent optical properties throughout the optical region from infrared to ultraviolet. Optical properties are studied along both parallel (||) and perpendicular ( ) polarization directions. The complex dielectric function (ε) and the complex refractive index (N) are calculated. The calculated values of ε and N enable us to analyze optical absorption, reflectivity, conductivity, and the electron loss function. Inferences from the study of optical properties are presented. In general the optical properties are found to be enhanced compared to its corresponding single layer. The further study brings out greater inferences towards their direct application in the optical industry through a wide range of the optical spectrum.

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.

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.

BAND STRUCTURE, HARDNESS, THERMODYNAMIC AND OPTICAL PROPERTIES OF SUPERCONDUCTING Nb2AsC, Nb2InC AND Mo2GaC

2013 ◽  
Vol 02 (02) ◽  
pp. 1350007 ◽  
Author(s):  
M. A. HADI ◽  
M. S. ALI ◽  
S. H. NAQIB ◽  
A. K. M. A. ISLAM
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Vickers Hardness ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Population Analysis ◽  
Debye Model ◽  
Electronic Band ◽  
Specific Heats ◽  
First Time

First-principles investigation of the geometry, electronic band structure, Vickers hardness, thermodynamic and optical properties of three superconducting MAX compounds Nb 2 AsC , Nb 2 InC and Mo 2 GaC have been carried out by the plane-wave pseudopotential method based on density functional theory (DFT) implemented in the CASTEP code. The theoretical Vickers hardness has been studied by means of Mulliken bond population analysis and electronic densities of states. The thermodynamic properties such as the temperature and pressure dependent bulk modulus, Debye temperature, specific heats and thermal expansion coefficient of the three 211 MAX phases are derived from the quasi-harmonic Debye model with phononic effect for the first time. Furthermore, all the optical properties are determined and analyzed for the first time for two different polarization directions. The theoretical findings are compared with relevant experiments (where available) and the various implications are discussed in details.

scholarly journals Intriguing electronic, optical and photocatalytic performance of BSe, M2CO2 monolayers and BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 42-52
Author(s):  
M. Munawar ◽  
M. Idrees ◽  
Iftikhar Ahmad ◽  
H. U. Din ◽  
B. Amin
Keyword(s):  
Density Functional Theory ◽  
Band Structure ◽  
Density Functional ◽  
Photocatalytic Performance ◽  
Electronic Band Structure ◽  
Van Der Waals ◽  
Density Functional Theory Calculations ◽  
Van Der Waals Heterostructures ◽  
Electronic Band ◽  
Functional Theory

Using density functional theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M2CO2 (M = Ti, Zr, Hf) monolayers and their corresponding BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures.

High Resolution Optical Spectroscopy of Free Exciton and Electronic Band Structure near the Fundamental Gap in 4H SiC

2018 ◽  
Vol 924 ◽  
pp. 239-244 ◽  
Author(s):  
Walter M. Klahold ◽  
Wolfgang J. Choyke ◽  
Robert P. Devaty
Keyword(s):  
Absorption Spectrum ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Free Exciton ◽  
Electron Mass ◽  
Electronic Band ◽  
Wavelength Resolution ◽  
Primary Origin ◽  
Valence Bands

We use thick, relatively high purity 4H SiC boule material to measure the wavelength modulated absorption spectrum with improved wavelength resolution and sensitivity with respect to previous work. We observe several small 0.6 ± 0.1 meV splittings, which we attribute to electron mass anisotropy and electron-hole exchange interaction. In addition, we identify several features in the absorption spectrum as signatures of nonparabolicity in the free exciton dispersion relations, the primary origin of which is likely the nonparabolic energy dispersion of the valence bands, as revealed by published band structure calculations based on density functional theory.

scholarly journals Electronic band structure, optical, dynamical and thermodynamic properties of cesium chloride (CsCl) from first-principles

2015 ◽  
Vol 6 ◽  
pp. A7 ◽  
Author(s):  
Suat Bingol ◽  
Bahattin Erdinc ◽  
Harun Akkus
Keyword(s):  
Thermodynamic Properties ◽  
Band Structure ◽  
Density Of States ◽  
Ground State ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Cesium Chloride ◽  
Total Density ◽  
Electronic Band ◽  
Ground State Properties

The geometric structural optimization, electronic band structure, total density of states for valence electrons, density of states for phonons, optical, dynamical, and thermodynamical features of cesium chloride have been investigated by linearized augmented plane wave method using the density functional theory under the generalized gradient approximation. Ground state properties of cesium chloride are studied. The calculated ground state properties are consistent with experimental results. Calculated band structure indicates that the cesium chloride structure has an indirect band gap value of 5.46 eV and is an insulator. From the obtained phonon spectra, the cesium chloride structure is dynamically stable along the various directions in the Brillouin zone. Temperature dependent thermodynamic properties are studied using the harmonic approximation model.

Establishment of Structural and Elastic Properties of Titanate Compounds Based on Pb, Sn and Ge by First-Principles Calculation

2014 ◽  
Vol 510 ◽  
pp. 57-62 ◽  
Author(s):  
N.H. Hussin ◽  
M.F.M. Taib ◽  
N.A. Johari ◽  
F.W. Badrudin ◽  
O.H. Hassan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Computer Code ◽  
Lattice Parameter ◽  
First Principles Calculation ◽  
Electronic Band ◽  
Equilibrium Lattice Parameter ◽  
Indirect Band Gap

Structural, electronic, and optical properties of PbTiO3, SnTiO3, and GeTiO3 tetragonals (P4mm, 99 space group) were investigated using density functional theory as implemented in pseudo-potential plane wave in CASTEP computer code. The calculated equilibrium lattice parameter, electronic band structure, and optical properties for PbTiO3 (reference compound) are in good agreement with the available experiment data. The result also shows that GeTiO3 has a higher tetragonality (c/a=1.18) compared with SnTiO3 (c/a=1.15) and PbTiO3 (c/a=1.05). Calculations of the elastic constants of PbTiO3, SnTiO3, and GeTiO3 tetragonals show that they are mechanically stable. The electronic band structure shows that PbTiO3 has higher indirect band gap at X-G compared with SnTiO3 and GeTiO3, as explained in detail by the optical properties of ATiO3 (A=Pb, Sn, Ge) through the refractive index and absorption coefficient.

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