FIRST PRINCIPLES STUDY OF THE ELECTRONIC STRUCTURE AND FERROMAGNETISM OF THE V-DOPED BN(5, 5) NANOTUBE

2008 ◽  
Vol 22 (18) ◽  
pp. 1749-1756 ◽  
Author(s):  
K. H. HE ◽  
G. ZHENG ◽  
G. CHEN ◽  
M. WAN ◽  
G. F. JI
Keyword(s):  
Electronic Structure ◽  
Magnetic Moment ◽  
First Principles ◽  
Generalized Gradient ◽  
Half Metallic ◽  
Ferromagnetic Properties ◽  
Generalized Gradient Approximation ◽  
First Principles Study ◽  
Spin Polarized

The structural, electronic and ferromagnetic properties of the V-doped BN(5, 5) are investigated by using first-principles spin-polarized calculations within generalized gradient approximation. The optimized structure shows that the V atom moves outwards and the hexagonal rings with the V atom experience significant distortion. The electronic structure indicates that the V-doped BN(5, 5) nanotube is half-metallic. The majority ferromagnetic moment comes from the V atom and slight magnetic moment is provided by the B atoms which are near to the V atom, while a little negative magnetic moment is contributed by the N atoms.

FIRST-PRINCIPLES STUDY OF THE EFFECTS OF THE OXYGEN VACANCY ON ELECTRONIC STRUCTURE AND FERROMAGNETISM OF Sn2 Co2O8-δ

2010 ◽  
Vol 24 (14) ◽  
pp. 2229-2235
Author(s):  
KAIHUA HE ◽  
GUANG ZHENG ◽  
HANLIE HONG ◽  
MIAO WAN ◽  
GUANGFU JI
Keyword(s):  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Magnetic Moment ◽  
First Principles ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Spin Magnetic Moment ◽  
Metallic Behavior ◽  
Half Metallic ◽  
Single Oxygen

The electronic structure and ferromagnetism of Sn 2 Co 2 O 8 and Sn 2 Co 2 O 7 have been investigated based on the first-principles plane-wave pseudopotential method within the generalized gradient approximation. The calculated results reveal that the oxygen vacancy plays an important role in the electronic structure and ferromagnetism. The Sn 2 Co 2 O 8 shows half-metallic behavior, but by introducing single oxygen vacancy, the half-metallic transits to metallic behavior. At the same time, the spin magnetic moment of every Co atom and the total magnetic moment change greatly. For Sn 2 Co 2 O 8 and Sn 2 Co 2 O 7, the total spin magnetic moments are 1.99 and 3.49 uB, respectively.

First principles study of the structural, electronic and optical properties of crystalline o-phenanthroline

2016 ◽  
Vol 30 (14) ◽  
pp. 1650077 ◽  
Author(s):  
Hajar Nejatipour ◽  
Mehrdad Dadsetani
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Binding Energies ◽  
Many Body ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Independent Particle ◽  
Excitonic Effects ◽  
Comprehensive Study

In a comprehensive study, structural properties, electronic structure and optical response of crystalline o-phenanthroline were investigated. Our results show that in generalized gradient approximation (GGA) approximation, o-phenanthroline is a direct bandgap semiconductor of 2.60 eV. In the framework of many-body approach, by solving the Bethe–Salpeter equation (BSE), dielectric properties of crystalline o-phenanthroline were studied and compared with phenanthrene. Highly anisotropic components of the imaginary part of the macroscopic dielectric function in o-phenanthroline show four main excitonic features in the bandgap region. In comparison to phenanthrene, these excitons occur at lower energies. Due to smaller bond lengths originated from the polarity nature of bonds in presence of nitrogen atoms, denser packing, and therefore, a weaker screening effect, exciton binding energies in o-phenanthroline were found to be larger than those in phenanthrene. Our results showed that in comparison to the independent-particle picture, excitonic effects highly redistribute the oscillator strength.

Study of the enhanced electronic and thermoelectric (TE) properties of ZrxHf1−x−yTayNiSn: a first principles study

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 95353-95359 ◽  
Author(s):  
D. P. Rai ◽  
A. Shankar ◽  
Sandeep Sandeep ◽  
M. P. Ghimire ◽  
R. Khenata ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
First Principles Study

A density functional theory (DFT) approach employing generalized gradient approximation (GGA) and the modified Becke Johnson (TB-mBJ) potential has been used to study the electronic and thermoelectric (TE) properties of ZrxHf1−x−yTayNiSn.

FIRST-PRINCIPLES STUDY OF MAGNETISM AND DEFECT STATE PROPERTIES OF ANTIPEROVSKITE GaC1-xMn3

2010 ◽  
Vol 24 (10) ◽  
pp. 953-962 ◽  
Author(s):  
L. HUA ◽  
L. WANG ◽  
L. F. CHEN
Keyword(s):  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Unit Cell Volume ◽  
Magnetic Transition ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Spin Polarized ◽  
Volume Decrease

We have investigated the electronic and magnetic properties of GaC 1-x Mn 3 (x = 0, 0.125, 0.25) using first-principles density functional theory within the generalized gradient approximation (GGA) + U schemes. The crystal structures of the compounds are cubic for x = 0, 0.125, 0.25. The lattice parameters and unit cell volume decrease as the C vacancy increase. Our spin polarized calculations give metallic ground state for x = 0, 0.125, 0.25. The magnetic structure for x = 0, 0.125 are antiferromagnetic, while for x = 0.25 it is ferromagnetic. From the density of states (DOS), the hybridization between the C 2p and Mn 3d state is the main reason for magnetic transition.

scholarly journals First Principles Study of Cerium Monochalcogenides

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Recep Eryiğit
Keyword(s):  
Experimental Data ◽  
Plane Wave ◽  
Theoretical Investigation ◽  
First Principles ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
First Principles Study ◽  
Dynamical Properties ◽  
Good Agreement

A theoretical investigation of structural, magnetic, electronic, and lattice dynamical properties of cerium monochalcogenides using the generalized gradient approximation (GGA) +Uwithin ultrasoft pseudopotentials and a plane-wave basis is presented. All the calculated quantities, except the local magnetic moments, are found to be in good agreement with the experimental data. The lattice dynamical results indicate a strong chalcogenide dependence for the anomalous features of the phonon dispersions.

Sign in / Sign up

Export Citation Format

Share Document