scholarly journals Tuning Electronic Structures of BN and C Double-Wall Hetero-Nanotubes

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xueran Liu ◽  
Meijun Han ◽  
Xinjiang Zhang ◽  
Haijun Hou ◽  
Shaoping Pang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Electric Field ◽  
Electronic Structures ◽  
Density Functional ◽  
Transverse Electric ◽  
First Principle ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Double Wall

First principle calculations based on density functional theory with the generalized gradient approximation were carried out to investigate the energetic and electronic properties of carbon and boron nitride double-wall hetero-nanotubes (C/BN-DWHNTs) with different chirality and size, including an armchair (n,n) carbon nanotube (CNT) enclosed in (m,m) boron nitride nanotube (BNNT) and a zigzag (n, 0) CNT enclosed in (m, 0) BNNT. The electronic structure of these DWHNTs under a transverse electric field was also investigated. The ability to tune the band gap with changing the intertube distance (di) and imposing an external electric field (F) of zigzag DWHNTs provides the possibility for future electronic and electrooptic nanodevice applications.

scholarly journals New polymorphic varieties of boron nitride with graphene-like structures

2021 ◽  
Vol 13 (3) ◽  
pp. 349-354
Author(s):  
Dmitry S. Ryashnetsev ◽  
◽  
Eugeny A. Belenkov ◽  
Keyword(s):  
Boron Nitride ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Geometric Optimization ◽  
First Principle ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory ◽  
Nitride Layers

First-principle calculations of the structure and electronic properties of four new polymorphic varieties of graphene-like boron nitride, the structure of which is similar to the structure of graphene polymorphs, the atoms in which are in the spirit of different structural positions, were performed by the density functional theory method in the generalized gradient approximation. As a result of the studies carried out, the possibility of stable existence of three monoatomic boron nitride layers: BN-L4-6-8a, BN-L4-6-8b and BN-L4-10 has been established. The BN-L4-12 layer is transformed into the BN-L4-6-8 layer during geometric optimization. The lengths of interatomic bonds in boron nitride monolayers vary in the range 1.4353 Å ÷ 1.4864 Å, and the bond angles in the range 84.05° ÷ 152.26°. The band gap of the BN layers varies from 3.16 eV to 3.90 eV. Sublimation energies are in the range from 16.67 eV/(BN) to 17.61 eV/(BN).

First-Principle Study of Electronic Structure and Stability of Ru1-xPdxZr

2013 ◽  
Vol 798-799 ◽  
pp. 151-156
Author(s):  
You Cai Yang ◽  
Ming Xie ◽  
Ji Ming Zhang ◽  
Man Men Liu ◽  
Yong Tai Chen ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Martensite Transformation ◽  
Density Functional ◽  
Ternary Phase ◽  
Theoretical Study ◽  
First Principle ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Mixing Energy ◽  
Generalized Gradient Approximation

A theoretical study on Ru1-xPdxZr solid solutions has been carried out by means of periodic density functional theory (DFT) at generalized gradient approximation (GGA) level. Stability and martensite transformation analysis were performed based on the formation energy and electronic structures. The results show that the ternary phase Ru2Pd6Zr8is stable because the de-mixing energy of Ru2Pd6Zr8is-0.05eV. The calculated cohesive energy, bond length and density of states showed that the orthorhombic-Ru2Pd6Zr8is more stable than bcc-Ru2Pd6Zr8, for the martensite transformation occurs when about 70% of the Ru atoms are replaced by Pd atoms. The studies provide a theoretical basis to the development and application of Ru1-xPdxZr solid solution.

Density Functional Calculations on Electronic and Magnetic Properties of Fe-Pt Systems

2005 ◽  
Vol 475-479 ◽  
pp. 3103-3106 ◽  
Author(s):  
You Song Gu ◽  
Jian He ◽  
Zhen Ji ◽  
Xiao Yan Zhan ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Electronic Structures ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Experimental Values ◽  
Pseudo Potential

The electronic structures and magnetic properties of Fe-Pt systems were calculated by CASTEP codes, which employed density functional theory, generalized gradient approximation (GGA), Perdew Burke Ernzerh exchange correlation, Pulay density-mixing scheme and Ultra Soft pseudo potential. The band structures and density of states (DOS) were calculated, together with band populations and magnetic properties. The calculated results of α-Fe show the validatiy of this method in predication magnetic properties. It is found that as the Pt concentration increases, Fe 4s and 3d electrons decrease while 4p electrons increase, and the magnetic moment of Fe atom increases. Pt atoms also contribute to the magnetic moment due to polarization. The calculated magnetization agrees with experimental values quite well.

scholarly journals Energetics and electronic structures of perylene confined in carbon nanotubes

2018 ◽  
Vol 5 (6) ◽  
pp. 180359 ◽  
Author(s):  
Yuya Nagasawa ◽  
Takeshi Koyama ◽  
Susumu Okada
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional Theory ◽  
Ground State ◽  
Electronic Structures ◽  
Density Functional ◽  
Molecular Conformation ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Molecular Conformations ◽  
Generalized Gradient Approximation

The energetics and geometries of perylene encapsulated in carbon nanotubes (CNTs) have been investigated employing density functional theory using the generalized gradient approximation combined with the van der Waals correction. Our calculations show that the encapsulated perylene molecules possess two metastable molecular conformations with respect to the CNT wall, which are almost degenerate with each other. A standing conformation, with respect to the CNT wall, is the ground state conformation for a semiconducting (19,0)CNT, while a lying conformation is the ground state for a metallic (11,11)CNT. Cooperation and competition between perylene–perylene and perylene–CNT interactions cause these possible perylene conformations inside CNTs. However, the electronic structure of the CNT encapsulating the perylene molecules is found to be insensitive to the molecular conformation.

A comparative study of small 3d-metal oxide (FeO)n, (CoO)n, and (NiO)n clusters

2016 ◽  
Vol 18 (40) ◽  
pp. 27858-27867 ◽  
Author(s):  
G. L. Gutsev ◽  
K. G. Belay ◽  
K. V. Bozhenko ◽  
L. G. Gutsev ◽  
B. R. Ramachandran
Keyword(s):  
Density Functional Theory ◽  
Metal Oxide ◽  
Comparative Study ◽  
Electronic Structures ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Metal Oxide Clusters ◽  
Generalized Gradient Approximation

Geometrical and electronic structures of the 3d-metal oxide clusters (FeO)n, (CoO)n, and (NiO)n are computed using density functional theory with the generalized gradient approximation in the range of 1 ≤ n ≤ 10.

Electronic structure engineering of various structural phases of phosphorene

2016 ◽  
Vol 18 (27) ◽  
pp. 18312-18322 ◽  
Author(s):  
Sumandeep Kaur ◽  
Ashok Kumar ◽  
Sunita Srivastava ◽  
K. Tankeshwar
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Electric Field ◽  
Electronic Structures ◽  
Density Functional ◽  
Transverse Electric ◽  
Transverse Electric Field ◽  
Functional Theory ◽  
Vertical Pressure ◽  
Structure Engineering

We report the tailoring of the electronic structures of various structural phases of phosphorene (α-P, β-P, γ-P and δ-P) based homo- and hetero-bilayers through in-plane mechanical strains, vertical pressure and transverse electric field by employing density functional theory.

scholarly journals Electronic Properties of Hydrogenated Hexagonal Boron Nitride (h-BN): DFT Study

2019 ◽  
Vol 4 (2) ◽  
pp. 72-79
Author(s):  
B. Chettri ◽  
P. K. Patra ◽  
Sunita Srivastava ◽  
Lalhriatzuala ◽  
Lalthakimi Zadeng ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Hexagonal Boron Nitride ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

In this work, we have constructed the hydrogenated hexagonal boron nitride (h-BN) by placing hydrogen atom at different surface sites. The possibility of hydrogen adsorption on the BN surface has been estimated by calculating the adsorption energy. The electronic properties were calculated for different hydrogenated BNs. The theoretical calculation was based on the Density Functional Theory (DFT). The electron-exchange energy was treated within the most conventional functional called generalized gradient approximation. The calculated band gap of pure BN is 3.80 eV. The adsorption of two H-atoms at two symmetrical sites of B and N sites reduces the band gap value to 3.5 eV. However, in all other combination the systems show dispersed band at the Fermi level exhibiting conducting behavior. Moreover, from the analysis of band structure and Density Of States we can conclude that, the hydrogenation tunes the band gap of hexagonal boron nitride.

First-Principle Study of Structural and Electronic Properties of Ti-Doped SnO2

2013 ◽  
Vol 634-638 ◽  
pp. 2545-2549 ◽  
Author(s):  
Jing Kai Yang ◽  
Hong Li Zhao ◽  
Yan Zhu ◽  
Li Ping Zhao ◽  
Jian Li
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
First Principle ◽  
Generalized Gradient ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Calculation Results

The structural and electronic properties of Ti-doped SnO2with 6.25 at.% are investigated with the first principle calculations based on the density functional theory within the generalized gradient approximation. The calculation results indicate that the crystal structure of Sn0.9375Ti0.0625O2possesses a smaller volume; the bond length of Ti-O is shorter than that of Sn-O; the relative angle θ change value of Sn-O-Sn→Ti-O-Ti is about 1.07%. Ti-O bond possesses more covalent ingredient and stronger bond energy than Sn-O bond. After the replacement of one Ti atom, O atom bonded with Ti atom possessed fewer electrons, the ratio of charges possessed by Ti atom and O atom dose not agree with the stoichiometry of compound, create more holes at the top of VB of Sn0.9375Ti0.0625O2, and lead to the increase of the conductivity.

Structures and electronic properties of WmMon (m + n ≤ 7) clusters

2018 ◽  
Vol 32 (04) ◽  
pp. 1850041
Author(s):  
Zhicheng Yu ◽  
Xiurong Zhang ◽  
Peiying Huo ◽  
Kun Gao
Keyword(s):  
Ground State ◽  
Electronic Structures ◽  
Density Functional ◽  
Geometry Optimization ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Ground State Structures ◽  
The Stability ◽  
D Orbitals

Geometric and electronic structures of W[Formula: see text]Mo[Formula: see text] (m + n [Formula: see text] 7) clusters have been systematically calculated by density functional theory (DFT) at the generalized gradient approximation (GGA) level for ground-state structures. Geometry optimization shows that clusters are almost bipyramid structures with m + n [Formula: see text] 4. E[Formula: see text] of clusters is mainly dominated by W atoms. And the substitution of atoms between W and Mo in Mo[Formula: see text] or W[Formula: see text] (n [Formula: see text] 7) clusters enhances the stability of the original clusters. The calculated IE shows that W[Formula: see text]Mo, W[Formula: see text]Mo2, W[Formula: see text]Mo3 and WMo[Formula: see text] are relatively more stable in the chemical reaction. In addition, the magnetism of clusters mainly comes from valance d orbitals.

First-Principle Simulation of Ferromagnetism in Gd-Doped Mg2X (X=Si, Ge and Sn)

SPIN ◽  
2019 ◽  
Vol 09 (03) ◽  
pp. 1950010
Author(s):  
Y. El Ahmar ◽  
A. Hallouche ◽  
A. Dahani ◽  
A. Zaoui ◽  
S. Kacimi ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Magnetic Phase ◽  
Theoretical Data ◽  
Coulomb Repulsion ◽  
First Principle ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Pure Compounds ◽  
Experimental Values

Magnetic phase stability and electronic properties of Gd-doped Mg2X ([Formula: see text], Ge and Sn) were investigated by first-principle calculations based on density functional theory. The present calculations were performed using the Generalized Gradient Approximation (PBE-GGA) and the modified Becke–Johnson (mBJ-GGA). The 4[Formula: see text] electrons’ behavior has been investigated as a function of the Coulomb repulsion [Formula: see text] by varying it from 0[Formula: see text]eV to 8[Formula: see text]eV. The ground state properties for the pure compounds are consistent with experimental values and other theoretical data. All doped compounds are metallic and ferromagnetic with large Curie temperature values. It was found that both exchange potentials ([Formula: see text] and [Formula: see text]) provide a better description of the electronic structures of pure and doped systems than regular GGA and mBJ.

Sign in / Sign up

Export Citation Format

Share Document