Coupling of the electronic band structure with Ag phonon modes in Y123 and Y124 systems

The electronic and lattice properties of α-TiNX (X:F, Cl, Br, I) were investigated from first principles. Ab initio calculations for geometry optimization, electronic band structure and zone-center phonon calculations have been carried out by using plane-wave pseudopotential method which is not examined before. From the electronic structure calculation, band gaps have been found as 1.23 eV, 0.955 eV, 0.897 eV for TiNF , TiNCl , TiNBr while there is no band gap for TiNI . This result can separate TiNI from other metal nitride halides which are semiconductor. Band structure calculations showed that increasing the electropositivity of halogen atom in TiNX systems decreasing the fermi energy level or in other words shift the valance bonds to higher energy. Also zone center phonon modes show that the vibrational frequencies are increasing by atomic number of halogens. Heavier halogen atom makes the system vibrate more slowly and as expected to reduce vibrational frequency.

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Radiative Properties of GaAs From First Principles Calculations

Heat Transfer: Volume 1 ◽

10.1115/ht2008-56341 ◽

2008 ◽

Author(s):

Hua Bao ◽

Xiulin Ruan

Keyword(s):

Band Structure ◽

Dielectric Function ◽

First Principles ◽

Electronic Band Structure ◽

Golden Rule ◽

Radiative Properties ◽

Initial Structure ◽

Phonon Modes ◽

Electronic Band ◽

Near Ir

Spectral reflectance of GaAs from infrared (IR) to ultra-violet (UV) bands is calculated from first principles. We first calculate the spectral dielectric function which is determined by the response of GaAs to external electromagnetic field. Two mechanisms exist for different wavelengths, namely, phonon absorption in the far-IR region and the electronic absorption in the near-IR to UV region. With plane-wave pseudopotential method, we determined the dielectric function of GaAs with the the initial structure as the only input. For the far-IR region, phonon calculations are carried out. By analyzing the phonon modes, low-frequency dielectric constant is calculated. For the near-IR to UV band, the electronic band structure of GaAs is calculated, and the imaginary part of the dielectric function is determined from the band structure using Fermi’s Golden rule. The real part of spectral dielectric function is then derived from Kramer-Kronig transformation. The reflectance is then calculated using Maxwell’s equations.

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The electronic band structure of silicon

Physica ◽

10.1016/s0031-8914(54)80307-7 ◽

1954 ◽

Vol 3 (7-12) ◽

pp. 967-970

Author(s):

D JENKINS

Keyword(s):

Band Structure ◽

Electronic Band Structure ◽

Electronic Band

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RELATIVISTIC ELECTRONIC BAND STRUCTURE OF THE HEAVY METALS AND THEIR INTERMETALLIC COMPOUNDS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1972309 ◽

1972 ◽

Vol 33 (C3) ◽

pp. C3-57-C3-72 ◽

Cited By ~ 26

Author(s):

A. J. FREEMAN ◽

D. D. KOELLING

Keyword(s):

Heavy Metals ◽

Band Structure ◽

Intermetallic Compounds ◽

Electronic Band Structure ◽

Electronic Band

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THE ELECTRONIC BAND STRUCTURE OF V3Ga AND V3Si

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1972333 ◽

1972 ◽

Vol 33 (C3) ◽

pp. C3-223-C3-233 ◽

Cited By ~ 3

Author(s):

I. B. GOLDBERG ◽

M. WEGER

Keyword(s):

Band Structure ◽

Electronic Band Structure ◽

Electronic Band

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

International Journal of Computational Physics Series ◽

10.29167/a1i1p46-50 ◽

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.

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