scholarly journals Effect of Nitrogen Impurity on Electronic Properties of Boron Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Sandeep Kumar Jain ◽  
Pankaj Srivastava
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Nitrogen Doping ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Functional Theory ◽  
Impurity Atoms ◽  
Nitrogen Impurity ◽  
First Time

For the first time we present electronic band structure and density of states for nitrogen doped hexagonal ultrathin boron nanotubes in the framework of density functional theory. The considered models of nanotubes below 5 Å diameter are armchair (3,3), zigzag (5,0), and chiral (4,2). The impurity chosen for the study is nitrogen and concentration of impurity atoms is limited to two. The study reveals that (3,3) BNT retains its metallic nature after nitrogen doping. However, metallicity gets increased which is attributed by the excess electrons of nitrogen. Further, it also brings out that (5,0) BNT which is originally metal transforms into semiconductor after nitrogen interaction and the band gap at G point increases with the impurity. Moreover, the band gap of (4,2) BNT reduces significantly and turns into semimetal for nitrogen doping. Thus, the nitrogen impurity has the predominant effect on the electronic properties of BNTs and therefore can be regarded as suitable candidates for nanoelectronic and field emission devices.

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.

Structural, electronic, optical and thermal properties of CuXTe2 (X=Al, Ga, In) compounds: An ab-initio study

2019 ◽  
Vol 33 (07) ◽  
pp. 1950045
Author(s):  
R. Mahdjoubi ◽  
Y. Megdoud ◽  
L. Tairi ◽  
H. Meradji ◽  
Z. Chouahda ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Thermodynamic Conditions ◽  
Structure Density ◽  
First Time ◽  
Linearized Augmented Plane Wave

First-principles calculations of the structural, electronic, optical and thermal properties of chalcopyrite CuXTe2 (X[Formula: see text]=[Formula: see text]Al, Ga, In) have been performed within density functional theory using the full-potential linearized augmented plane wave (FP-LAPW) method, by employing for the exchange and correlation potential the approximations WC-GGA and mBJ-GGA. The effect of X cations replacement on the structural, electronic band structure, density of states and optical properties were highlighted and explained. Our results are in good agreement with the previous theoretical and experimental data. As far as we know, for the first time we find the effects of temperature and pressure on thermal parameters of CuAlTe2 and CuGaTe2 compounds. Thermal properties are very useful for optimizing crystal growth, and predict photovoltaic applications on extreme thermodynamic conditions.

Pressure Effect on the Electronic Properties of Cerium Monochalcogenides CeX (X=S, Se, Te) Using Modified Becke-Johnson Exchange Potential and LDA+U

2014 ◽  
Vol 925 ◽  
pp. 390-395
Author(s):  
Noureddine Amrane ◽  
Maamar Benkraouda
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Exchange Potential ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
The Density Functional Theory ◽  
Linearized Augmented Plane Wave

We present a systematic and comparative study of the electronic properties of CeX monochalcogenides, The density of state (DOS) and electronic band structure of CeX (X=S, Se, Te) have been calculated using the full-potential linearized augmented plane-wave (FP-LAPW) + local orbital (lo) method based on the density functional theory (DFT), which is implemented in WIEN2k code. The trends in the high pressure behavior of these systems are discussed. Four approximations for the exchange-correlation functional have been used, the GGA's of Perdew-Burke-Ernzherhof. (PBE08) , Engel-Vosko (EV93), a modified version of the exchange potential proposed by Becke and Johnson (MBJ), and LDA+U is used to calculate the band gaps at different pressures. All methods allow for a description of the Ce f electrons as either localized or delocalized, it is found that the underestimations of the bandgap by means of LDA-GGA and Engel-Vosko are considerably improved by using the modified Becke-Johnson (MBJ) potential for all compounds in the series, On the other hand, LDA+U, method gives good results for the lighter chalcogenides, but it fails to give good results for the heavier cerium monochalcogenides.

A BN analog of two-dimensional triphenylene-graphdiyne: stability and properties

Nanoscale ◽  
2019 ◽  
Vol 11 (18) ◽  
pp. 9000-9007 ◽  
Author(s):  
Imran Muhammad ◽  
Huanhuan Xie ◽  
Umer Younis ◽  
Yu Qie ◽  
Waseem Aftab ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Two Dimensional ◽  
Electronic Band ◽  
Functional Theory ◽  
The Stability ◽  
First Time ◽  
Recent Synthesis

Motivated by the feasibility of hybridizing C- and BN-units as well as the recent synthesis of a triphenylene-graphdiyne (TpG) monolayer, for the first time we explore the stability and electronic band structure of a Tp-BNyne monolayer composed of C-chains and the BN analog of triphenylene (Tp-BNyne) by using density functional theory.

scholarly journals Database of Wannier tight-binding Hamiltonians using high-throughput density functional theory

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Kevin F. Garrity ◽  
Kamal Choudhary
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
High Throughput ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Tight Binding ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Link Type

AbstractWannier tight-binding Hamiltonians (WTBH) provide a computationally efficient way to predict electronic properties of materials. In this work, we develop a computational workflow for high-throughput Wannierization of density functional theory (DFT) based electronic band structure calculations. We apply this workflow to 1771 materials (1406 3D and 365 2D), and we create a database with the resulting WTBHs. We evaluate the accuracy of the WTBHs by comparing the Wannier band structures to directly calculated spin-orbit coupling DFT band structures. Our testing includes k-points outside the grid used in the Wannierization, providing an out-of-sample test of accuracy. We illustrate the use of WTBHs with a few example applications. We also develop a web-app that can be used to predict electronic properties on-the-fly using WTBH from our database. The tools to generate the Hamiltonian and the database of the WTB parameters are made publicly available through the websites https://github.com/usnistgov/jarvis and https://jarvis.nist.gov/jarviswtb.

The Electronic Properties of Al-, P-Doped and Al, P Co-Doped Boron Nitride Nanotubes

2011 ◽  
Vol 399-401 ◽  
pp. 2215-2221 ◽  
Author(s):  
Miao Sun ◽  
Gong Lian Wu ◽  
Ting Ye ◽  
Hui Zhang ◽  
Zhao Di Yang ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Boron Nitride Nanotubes ◽  
Electronic Band ◽  
First Principle Calculation ◽  
Impurity Atoms ◽  
Impurity Doped ◽  
The Stability ◽  
Co Doped

The electronic properties of Al-, P-doped, and Al, P co-doped in a (6, 6) BN nanotubes were obtained using the first principle calculation based on the density functional theory. For the doped BNNTs, the structures are with ignorable deformation observed around the doping atoms. The analysis of the formation energies shows that aluminum replacement to be favorable, particularly in the case of the low concentration, and the stability of nanotubes has nothing to do with the doping position. The electronic band structure and DOS for the systems of Al-, and P-doped BNNTs all behave as impurity-doped widegap semiconductor. And as to the P-doped BNNTs, the conductivity becomes stronger with the higher concentration. Whereas, the results of the system of Al, P co-doped BNNTs illustrate that the electronic properties of nanotubes have nothing to do with the doping positions of impurity atoms.

scholarly journals Effect of Point Defects on Electronic Properties and Structure of Talc (001) Surface by First Principles

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Xindi Ma ◽  
Huicong Du ◽  
Ping Lan ◽  
Jianhua Chen ◽  
Lihong Lan
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Surface States ◽  
State Density ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Impurity Atoms ◽  
Electron State Density ◽  
Calculation Results ◽  
Impurity Defects

The surface structure and electronic properties of Mg vacancy defects on talc (001) and impurity defects with Fe, Mn, Ni, Al, and Ca replacing Mg atoms were calculated by using density functional theory. The calculation results show that the order of impurity substitution energy is Mn < Ni < Al < Ca < Fe. This indicates that Fe impurity defects are most easily formed in talc crystals. The covalent bonding between Si atoms and reactive oxygen atoms adjacent to impurity atoms is weakened and the ionic property is enhanced. The addition of Fe, Mn, and Ni atoms makes the surface of talc change from an insulator to a semiconductor and enhances its electrical conductivity. The analysis of electron state density shows that surface states composed of impurity atoms 4S orbital appear near the Fermi level.

scholarly journals Hydration Dependent Band Gap Tunability of Self-Assembled Phenylalanine-Tryptophan Nanotubes

2020 ◽  
Author(s):  
Hugo Souza ◽  
Antonio Chaves Neto ◽  
Francisco Sousa ◽  
Rodrigo Amorim ◽  
Alexandre Reily Rocha ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Electronic Properties ◽  
Building Block ◽  
Density Functional ◽  
Tight Binding ◽  
Water Molecules ◽  
Confined Water ◽  
Functional Theory ◽  
Tight Binding Method

In this work, we investigate the effects of building block separation of Phenylalanine-Tryptophan nanotube induced by the confined water molecules on the electronic properties using density-functional theory based tight-binding method. <div><br></div>

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.

scholarly journals Ab-initio study of the orthorhombic ndmno3 perovskite

2014 ◽  
Vol 70 (a1) ◽  
pp. C1806-C1806
Author(s):  
Samir Bentata ◽  
Bouabdellah Bouadjemi ◽  
Tayeb Lantri ◽  
Wissem Benstaali
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Total Density ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Ferromagnetic Ground State ◽  
Total Density Of States

We investigate the structural, electronic and magnetic properties of the orthorhombic Perovskite oxyde NdMnO3 through density-functional-theory (DFT) calculations using both generalized gradient approximation GGA+U, where U is on-site Coulomb interaction correction. The electronic band structure, the partial and total density of states (DOS) and the magnetic moment are determined. The results show a half-metallic ferromagnetic ground state for the orthorhombic NdMnO3.

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