DFT calculations of tin dioxide crystals containing heavily-doped fluorine

2014 ◽  
Vol 13 (08) ◽  
pp. 1450069 ◽  
Author(s):  
Freddy Marcillo ◽  
Arvids Stashans
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Tin Dioxide ◽  
Empirical Studies ◽  
Experimental Fact ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Heavily Doped

First-principles calculations based on the density functional theory (DFT) within the generalized gradient approximation have been used in the present research. Fluorine doping in the SnO 2 crystals has been carried out considering a number of different defect concentrations. Dopant influence upon structural, electronic and electrical properties of the tin dioxide has been discussed in detail. The system presents n-type electrical conductivity relating our work directly to a number of empirical studies in this area. An experimental fact that n-type conductivity tends to decrease at rather high fluorine impurity rates has been explained at the theoretical level.

Quantum-chemical study of nitrogen and magnesium co-doping in α-Cr2O3

2016 ◽  
Vol 30 (14) ◽  
pp. 1650219
Author(s):  
Soraya Jácome ◽  
Arvids Stashans
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Text Type ◽  
Co Doping ◽  
The Density Functional Theory

Study of corundum-type chromium oxide ([Formula: see text]-Cr2O3) crystal doped with the nitrogen and magnesium impurities has been carried out through the use of first-principles calculations based on the density functional theory (DFT) and generalized gradient approximation (GGA). Three cases corresponding different impurity–impurity distances have been considered. Structural, electronic and magnetic properties have been studied for all co-doping cases. The [Formula: see text]-type electrical conductivity was found when distance between the Mg and N atoms is equal to 4.10 Å. The results obtained are consistent with the available experimental data.

First-Principles Calculations on Pure and Ga-Doped Anatase TiO2

2010 ◽  
Vol 156-157 ◽  
pp. 1385-1388
Author(s):  
Rui Qing Xu ◽  
Lan Fang Yao ◽  
Lin Li ◽  
Shuo Wang ◽  
Lin Lin Tian ◽  
...  
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Correlation Energy ◽  
Anatase Tio2 ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Band Gap Narrowing

First-principles calculations using the plane-wave pseudo-potential (PWPP) method based on the density functional theory (DFT) is employed to study the crystal structure, band gap, density of states of anatase TiO2 doped with gadolinium (Gd). The generalized gradient approximation (GGA) based on exchange-correlation energy optimization is employed to calculate them. The calculated results demonstrate that the mixing of gadolinium dopants induces states with original titanium 3d and oxygen 2p valence band attributes to the band gap narrowing. This can enhance the photocatalytic activity of anatase TiO2.

Hydrogen storage on multiple palladium-decorated graphene

2021 ◽  
Author(s):  
Saran Lamichhane ◽  
Nurapati Pantha ◽  
Bipin Khatry ◽  
Prakash Parajuli ◽  
Narayan Prasad Adhikari
Keyword(s):  
Hydrogen Storage ◽  
First Principles ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Magnetic Characteristics ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Symmetry Break

The geometries, structural stability, electrical and magnetic characteristics of pure and multiple palladium (Pd)-adsorbed graphene, followed by hydrogen adsorption, are investigated using first-principles calculations with the density functional theory. In the DFT-D2 technique, first-principles computations with the van der Waals interaction are done using the generalized gradient approximation. In a [Formula: see text] supercell, the adsorption energy per Pd atom is found to be 1.20 eV in the optimal adsorption shape. The bandgap of 51 meV has opened in multiple Pd-decorated graphene, according to band calculations. This band’s opening is ascribed to a symmetry break. The binding energy for hydrogen adsorption in optimal double Pd-decorated graphene was determined to be in the range of (0.14–0.73) eV per hydrogen molecule, indicating that Pd-decorated graphene might be used as a hydrogen storage material.

Electronic Structure and Optical Properties of InN: A First-Principles Study

2013 ◽  
Vol 760-762 ◽  
pp. 425-428
Author(s):  
Wei Hua Wang ◽  
Guo Zhong Zhao
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Potential Method ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Density ◽  
Pseudo Potential

The electronic properties and the optical properties of wurtzite InN are studied by the first-principles calculations based on the density functional theory. The calculations are based on the Generalized-Gradient Approximation (GGA) and implemented in Plane Wave Self-Consist Field (PWSCF). The optical properties of InN are investigated by the pseudo-potential method with PBEsol-GGA within the WIEN2K program. Band structure, density of states and dielectric functions are calculated detailedly. The energy transitions are observed and compared existing data at critical points. Moreover the new peak in between the region 12 eV to 14 eV should be due to transitions from the In-5p states to the N-2s states.

Electronic structure of cubic BaTbO3 from first-principles pseudopotential calculations

2006 ◽  
Vol 84 (2) ◽  
pp. 115-120 ◽  
Author(s):  
G Y Gao ◽  
K L Yao ◽  
Z L Liu
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Pseudopotential Calculations ◽  
Correlation Potential ◽  
Density Contour

First-principles calculations of the electronic structure are performed for cubic BaTbO3 using the plane-wave pseudopotential method within the framework of density functional theory and using the generalized gradient approximation for the exchange-correlation potential. Our calculations show that cubic BaTbO3 is metallic, and that this metallic character is mainly governed by the Tb 4f electrons and the hybridization between the Tb 5d and O 2p states. From the analysis of the density of states, band structure, and charge density contour, we find that the chemical bonding between Tb and O is covalent while that between Ba and TbO3 is ionic. PACS Nos.: 71.15.Mb, 71.20.-b

scholarly journals Electronic, optical and thermoelectric properties of Fe2ZrP compound determined via first-principles calculations

RSC Advances ◽  
2019 ◽  
Vol 9 (44) ◽  
pp. 25900-25911 ◽  
Author(s):  
Esmaeil Pakizeh ◽  
Jaafar Jalilian ◽  
Mahnaz Mohammadi
Keyword(s):  
Density Functional Theory ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Density Functional ◽  
Transport Theory ◽  
First Principles Calculations ◽  
Boltzmann Transport ◽  
Functional Theory ◽  
Boltzmann Transport Theory ◽  
The Density Functional Theory

In this study, based on the density functional theory and semi-classical Boltzmann transport theory, we investigated the structural, thermoelectric, optical and phononic properties of the Fe2ZrP compound.

scholarly journals Effect of Defects on Spontaneous Polarization in Pure and Doped LiNbO3: First-Principles Calculations

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 100 ◽  
Author(s):  
Weiwei Wang ◽  
Dahuai Zheng ◽  
Mengyuan Hu ◽  
Shahzad Saeed ◽  
Hongde Liu ◽  
...  
Keyword(s):  
Spontaneous Polarization ◽  
First Principles ◽  
Density Functional ◽  
Lattice Distortion ◽  
Stable Structure ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Specific Configuration ◽  
The Relationship

Numerous studies have indicated that intrinsic defects in lithium niobate (LN) dominate its physical properties. In an Nb-rich environment, the structure that consists of a niobium anti-site with four lithium vacancies is considered the most stable structure. Based on the density functional theory (DFT), the specific configuration of the four lithium vacancies of LN were explored. The results indicated the most stable structure consisted of two lithium vacancies as the first neighbors and the other two as the second nearest neighbors of Nb anti-site in pure LN, and a similar stable structure was found in the doped LN. We found that the defects dipole moment has no direct contribution to the crystal polarization. Spontaneous polarization is more likely due to the lattice distortion of the crystal. This was verified in the defects structure of Mg2+, Sc3+, and Zr4+ doped LN. The conclusion provides a new understanding about the relationship between defect clusters and crystal polarization.

scholarly journals Ab initio study of optical and bulk properties of cesium lead halide perovskite solid solutions

2019 ◽  
Vol 33 (31) ◽  
pp. 1950386
Author(s):  
Vladimir Saleev ◽  
Alexandra Shipilova
Keyword(s):  
Solid Solutions ◽  
First Principles ◽  
Disordered Systems ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Bulk Properties ◽  
The Density Functional Theory ◽  
Halide Perovskite ◽  
Lead Halide

The first-principles calculations of band gaps and bulk moduli of cesium lead halide perovskite solid solutions, [Formula: see text] and [Formula: see text], are performed at the level of general gradient approximation of the density functional theory. We use supercell approach for computational modeling of disordered systems, which gives a description of the properties of the structure baasing on the average over a set of multiple configurations, namely distributions of different species over a given set of atomic positions. The calculations were performed with the CRYSTAL14 program package. The dependence of the band gap and bulk modulus on the content [Formula: see text] are investigated over the whole range [Formula: see text].

First Principles Calculations of Electronic Structure and Optical Properties of Cu-Doped SnS2

2013 ◽  
Vol 373-375 ◽  
pp. 1965-1969
Author(s):  
Kun Nan Qin ◽  
Ling Zhi Zhao ◽  
Yong Mei Liu ◽  
Fang Fang Li ◽  
Chao Yang Cui
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Optical Absorption Coefficient ◽  
Impurity Level ◽  
First Principles Calculations ◽  
Absorption Region ◽  
Functional Theory ◽  
The Density Functional Theory

The electronic structure and optical properties of Cu-doped SnS2with Sn-substituted content of 0, 12.5 and 37.5 at.% were successfully calculated by the first principles plane-wave pseudopotentials based on the density functional theory. It is found that the intermediate belts appear near the Fermi level and the energy band gap becomes narrower after the doping of the Cu atoms. The absorption peaks show a remarkable redshift and the absorption region broadens relatively after introducing acceptor impurity level. When Sn atoms of 37.5 at% were substituted by Cu, the optical absorption coefficient is significantly improved in the frequency range below 5.58 eV and over 8.13 eV.

Pressure-Induced Tunable Magnetism and Half-Metallic Stability in Co2FeGa Heusler Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1303-1306
Author(s):  
Qin Xiang Gao
Keyword(s):  
Fermi Level ◽  
First Principles ◽  
Density Functional ◽  
High Energy ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
The Density Functional Theory

Using the first-principles calculations within the density functional theory (DFT), we have investigated the structure, magnetism and half-metallic stability of Co2FeGa Heusler compound under pressure from 0 to 50GPa. The results revel that the lattice constant is gradually shrank and total magnetic moment in per unit slightly decreased with increasing pressure, respectively. Moreover, with the increase of the pressure, the Fermi level will move towards high-energy orientation. When the pressure reaches at 30GPa the most stable half-metallicity is observed which the Fermi level is located at the middle of the spin-minority gap.

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