PSJD - Yadda

1

Theoretical study of NO3− interacting with carbon nanotube

100%

Guerini S., Azevedo D., Lima M., Zanella I., Filho J.

Open Physics

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2008

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vol. 6

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issue 1

105-108

EN

This paper deals with quantum mechanical interaction of no 3− with (5,5) and (8,0) swcnts. To perform this we have made an ab initio calculation based on the density functional theory. In these framework the electronic density plays a central role and it was obtained of a self-consistent field form. It was observed through binding energy that NO3− molecule interacts with each nanotube in a physisorption regime. We propose these swcnts as a potential filter device due to reasonable interaction with NO3− molecule. Besides this type of filter could be reusable, therefore after the filtering, the swcnts could be separated from NO3− molecule.

2

First-principle calculations for electronic structure and bonding properties in layered Na2Ti3O7

100%

An Y., Li Z., Xiang H., Huang Y., Shen J.

Open Physics

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2011

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vol. 9

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issue 6

1488-1492

EN

First-principles calculations of Na2Ti3O7 have been carried out with density-functional theory (DFT) and ultrasoft pseudopotentials. The electronic structure and bonding properties in layered Na2Ti3O7 have been studied through calculating band structure, density of states, electron density, electron density difference and Mulliken bond populations. The calculated results reveal that Na2Ti3O7 is a semiconductor with an indirect gap and exhibits both ionic and covalent characters. The stability of the (Ti3O7)2− layers is attributed to the covalent bonding of strong interactions between O 2p and Ti 3d orbitals. Furthermore, the O atoms located in the innerlayers interact more strongly with the neighboring Ti atoms than those in the interlayer regions. The ion-exchange property is due to the ionic bonding between the Na+ and (Ti3O7)2− layers, which can stabilize the interlayers of layered Na2Ti3O7 structure.

3

The nonlinear optical susceptibility and electro-optic tensor of ferroelectrics: first-principle study

100%

Cabuk S.

Open Physics

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2012

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vol. 10

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issue 1

239-252

EN

The nonlinear optical properties of some ABO3 materials (BaTiO3, KNbO3, LiTaO3 and LiNbO3) are studied by density functional theory (DFT) in the local density approximation (LDA) expressions based on first-principle calculations. Our goals are to give the details of the calculations for linear and nonlinear optical properties, including the linear electro-optic (EO) tensor for some ABO3 structures with oxygen octahedral structures using first-principles methods. These results can then be used in the study of the physics of ferroelectrics, specifically, we present calculations of the second harmonic generation response coefficient X ijk(2) (−2ω, ω, ω) over a large frequency range for ABO3 crystals. The electronic linear EO susceptibility X ijk(2) (−ω, ω,0) is also evaluated below the band gap. These results are based on a series of the LDA calculations using DFT. Results for X ijk(2) (−ω, ω,0) are in agreement with experiments below the band gap. The results are compared with the theoretical calculations and the available experimental data.

4

Under Pressure DFT Investigations on Optical and Electronic Properties of PbZrO₃

100%

Nazir G., Tariq S., Afaq A., Mahmood Q., Saad S., Mahmood A., Tariq S.

Acta Physica Polonica A

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2018

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vol. 133

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issue 1

105-113

EN

In this article, density functional theory has been used to investigate the structural and optoelectronic properties of PbZrO₃ (PZO) under pressure from 0 to 350 GPa. In order to achieve ground state structural stability, generalized gradient approximations has been utilized. By studying electronic properties, indirect band-gap nature of PZO appears to change at 15 GPa to direct band-gap. Optical analysis include under pressure responses of real and imaginary parts of dielectric function, optical conductivity, optical absorption coefficient, energy loss function, refractive index, reflectivity and extinction coefficient. Most of the results have been found to be consistent with literature. Study reveals that static dielectric constant and band-gap are in accordance with the Penn model which validates our computed results. Moreover, static dielectric constant and static refractive index directly increases with pressure. Material preserves its positive value of refractive index at all pressures and therefore, it is not a negative index metamaterial. Plasma frequency increases directly with pressure that destabilize the under study material. Our results could be very useful for developing novel optoelectronic devices based on PZO suitable to work under extreme conditions.

5

Structural and electronic properties of zincblende phase of TlxGa1−x AsyP1−y quaternary alloys: First-principles study

100%

Gulebaglan S., Dogan E., Aycibin M., Secuk M., Erdinc B., Akkus H.

Open Physics

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2013

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vol. 11

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issue 12

1680-1685

EN

Using the first-principles band-structure method, we have calculated the structural and electronic properties of zincblende TlAs, TlP, GaAs and GaP compounds and their new semiconductor TlxGa1−x AsyP1−y quaternary alloys. Structural properties of these semiconductors are obtained with the Perdew and Wang local-density approximation. The lattice constants of TlxGa1−x As, TlxGa1−x P ternary and TlxGa1−x AsyP1−y quaternary alloys were composed by Vegard’s law. Our investigation on the effect of the doping (Thallium and Arsenic) on lattice constants and band gap shows a non-linear dependence for TlxGa1−x AsyP1−y quaternary alloys. The band gap of TlxGa1−x AsyP1−y , E g(x, y) concerned by the compositions x and y. To our awareness, there is no theoretical survey on TlxGa1−x AsyP1−y quaternary alloys and needs experimental verification.

6

B and N-doped double walled carbon nanotube: a theoretical study

100%

Mendes Lima W., Azevedo D., Guerini S.

Open Physics

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2010

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vol. 8

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issue 5

811-818

EN

The structural and electronic properties of boron and nitrogen atom substitutional doping in (8,0)@(13,0) (semiconductor@semiconductor) and (6,0)@(13,0) (metallic@semiconductor) double walled carbon nanotubes, were obtained by using the first-principle calculations based on the density functional theory. In this framework, the electronic density plays a central role and it was obtained from a self-consistent field form. When boron or nitrogen substitutes a carbon atom the structure remains practically the same with negligible deformation observed around defects in all configurations considered. The electronic band structure results indicate that the boron doped systems behave as a p-type impurity, however, the nitrogen doped systems behave as an n-type impurity. In all the systems investigated here, we found that, in the cases of semiconductor@semiconductor tubes, they were the easiest to incorporate a B atom in the outer-wall and an N atom in the inner-wall of the nanotube.

7

First-principles investigation of structural, electronic, optical and dynamical properties in CsAu

88%

Erdinc B., Soyalp F., Akkus H.

Open Physics

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2011

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vol. 9

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issue 5

1315-1320

EN

The structural, electronic, optical and dynamical properties of CsAu compound in the CsCl(B2) phase were investigated using the density functional theory (DFT) within the generalized gradient approximation (GGA). The calculated lattice constant, static bulk modulus and first-order pressure derivative of the bulk modulus are reported and compared with previous experimental and theoretical calculations. The calculated electronic band structure for this compound is in good agreement with available theoretical and experimental studies. The present band calculation indicates that CsAu compound has an indirect gap at R→X points. Furthermore, the linear photon-energy-dependent dielectric functions have been calculated. For the first time, the electronic structure results are used, within the implementation of a linear-response technique, for calculations of phonon properties.

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Theoretical study of NO3− interacting with carbon nanotube

First-principle calculations for electronic structure and bonding properties in layered Na2Ti3O7

The nonlinear optical susceptibility and electro-optic tensor of ferroelectrics: first-principle study

Under Pressure DFT Investigations on Optical and Electronic Properties of PbZrO₃

Structural and electronic properties of zincblende phase of TlxGa1−x AsyP1−y quaternary alloys: First-principles study

B and N-doped double walled carbon nanotube: a theoretical study

First-principles investigation of structural, electronic, optical and dynamical properties in CsAu