scholarly journals Effect of point defects on the electronic density of states of ScN studied by first-principles calculations and implications for thermoelectric properties

2012 ◽  
Vol 86 (19) ◽  
Author(s):  
Sit Kerdsongpanya ◽  
Björn Alling ◽  
Per Eklund
Keyword(s):  
Thermoelectric Properties ◽  
Density Of States ◽  
Point Defects ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic Density ◽  
Electronic Density Of States

Chemical Bonding and Pseudogap in Zn- and Cd-based Compounds with Complex Hexagonal Structures

2003 ◽  
Vol 805 ◽  
Author(s):  
Y. Ishii ◽  
K. Nozawa ◽  
T. Fujiwara
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Chemical Bonding ◽  
First Principles ◽  
Electronic Structures ◽  
Unit Cell ◽  
First Principles Calculations ◽  
Electronic Density ◽  
Electronic Density Of States ◽  
Crystal Orbital

ABSTRACTElectronic structures of hexagonal Zn-Mg-Y and Cd58Y13 compounds are studied by first-principles calculations. Both of the systems show deep pseudogap in the electronic density of states near the Fermi level and considered to be stabilized electronically. To illustrate bonding nature of electronic wavefunctions, the crystal orbital Hamilton population (COHP) is calculated for neighboring pairs of atoms in the unit cell. It is found that the bonding nature is changed from bonding to anti-bonding almost exactly at the Fermi level for Zn-Zn and Cd-Cd bonds. On the contrary, for Zn/Cd-Y bonds, both of the states below and above the pseudogap behave as bonding ones. Possible effects of the p-d hybridization are discussed.

scholarly journals The Effect of Point Defects on the Electronic Density of States of ScMN2-Type (M = V, Nb, Ta) Phases

2019 ◽  
Vol 4 (3) ◽  
pp. 70 ◽  
Author(s):  
Robert Pilemalm ◽  
Sergei Simak ◽  
Per Eklund
Keyword(s):  
Density Of States ◽  
Point Defects ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Electronic Density ◽  
Functional Theory ◽  
Occupied State ◽  
Narrow Bandgap ◽  
Bandgap Semiconductors

ScMN2-type (M = V, Nb, Ta) phases are layered materials that have been experimentally reported for M = Ta and Nb. They are narrow-bandgap semiconductors with potentially interesting thermoelectric properties. Point defects such as dopants and vacancies largely affect these properties, motivating the need to investigate these effects. In particular, asymmetric peak features in the density of states (DOS) close to the highest occupied state is expected to increase the Seebeck coefficient. Here, we used first principles calculations to study the effects of one vacancy or one C, O, or F dopant on the DOS of the ScMN2 phases. We used density functional theory to calculate formation energy and the density of states when a point defect is introduced in the structures. In the DOS, asymmetric peak features close to the highest occupied state were found as a result of having a vacancy in all three phases. Furthermore, one C dopant in ScTaN2, ScNbN2, and ScVN2 implies a shift of the highest occupied state into the valence band, while one O or F dopant causes a shift of the highest occupied state into the conduction band.

scholarly journals Effect of point defects on the electronic density states of SnC nanosheets: First-principles calculations

2017 ◽  
Vol 7 ◽  
pp. 3209-3215 ◽  
Author(s):  
Soleyman Majidi ◽  
Amine Achour ◽  
D.P. Rai ◽  
Payman Nayebi ◽  
Shahram Solaymani ◽  
...  
Keyword(s):  
Point Defects ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic Density

Enhancement of thermoelectric performance of β-Zn4Sb3 through resonant distortion of electronic density of states doped with Gd

2015 ◽  
Vol 3 (22) ◽  
pp. 11768-11772 ◽  
Author(s):  
Baojin Ren ◽  
Mian Liu ◽  
Xiaoguang Li ◽  
Xiaoying Qin ◽  
Di Li ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Density Of States ◽  
Thermoelectric Performance ◽  
Electronic Density ◽  
Electronic Density Of States

The thermoelectric properties of Gd-doped β-Zn4Sb3 are investigated.

The Study of Electronic Density of States and Optical Properties of ZnO Nanotube by First-Principles

2015 ◽  
Vol 713-715 ◽  
pp. 2966-2969
Author(s):  
Yue Fan ◽  
Shao Chang Chen
Keyword(s):  
Optical Properties ◽  
Fermi Level ◽  
Density Of States ◽  
First Principles ◽  
Electronic Density ◽  
Electronic Density Of States ◽  
Zno Nanotube ◽  
Narrow Energy Range ◽  
Wide Energy ◽  
Better Than

In this paper, we studied the electronic density of states (DOS) and optical properties ZnO using first-principles method. We find that the electronic density of states was different in bulk ZnO and ZnO nanotube. The DOS of bulk ZnO spread at wide energy while the DOS of ZnO nanotube concentrated in a narrow energy range. The peak around-18 eV moved to a higher energy. The peaks more than Fermi level concentrated to the Fermi level, which meant the conductivity of ZnO nanotube was better than that of bulk ZnO. We also calculated the optical properties of ZnO nanotube. The optical properties showed that there were peaks around 8 eV, which may come from electrons transition between Zn 3dand O 2pstates. Our calculation provided a reference for the application of ZnO nanotube in optical devices.

Resonant distortion of electronic density of states and enhancement of thermoelectric properties of β-Zn4Sb3 by Pr doping

2013 ◽  
Vol 113 (12) ◽  
pp. 124901 ◽  
Author(s):  
Q. Q. Wang ◽  
X. Y. Qin ◽  
D. Li ◽  
R. R. Sun ◽  
T. H. Zou ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Density Of States ◽  
Electronic Density ◽  
Electronic Density Of States

Understanding The Nb-Ti-A1 System: First Principles Calculations

1994 ◽  
Vol 364 ◽  
Author(s):  
Michael J. Mehl
Keyword(s):  
High Temperature ◽  
Bulk Modulus ◽  
Total Energy ◽  
Crystal Structures ◽  
Lattice Constant ◽  
Density Of States ◽  
First Principles ◽  
First Principles Calculations ◽  
Electronic Density ◽  
Cubic Phases

AbstractThe discovery of ductile cubic phases in the Nb-Ti-Al system has led to increased study of these high-temperature intermetallics. I have performed first-principles calculations for ordered crystal structures in this system, paying particular attention to the Nb7Ti7Al2 structure. Somewhat surprisingly, the electronic density of states, lattice constant, and bulk modulus are nearly independent of the ordering of these materials, even though the changes in the total energy are significant.

Sign in / Sign up

Export Citation Format

Share Document