DENSITY FUNCTIONAL CALCULATION OF THE ELECTRONIC STRUCTURES OF SOME A5B6C7-TYPE CRYSTALS

2009 ◽  
Vol 23 (01) ◽  
pp. 97-104 ◽  
Author(s):  
HARUN AKKUS
Keyword(s):  
Density Functional ◽  
Density Functional Calculation ◽  
Generalized Gradient ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Pseudopotential Theory ◽  
The Density Functional Theory ◽  
Indirect Band Gap ◽  
Electronic Band Structures

The electronic band structures of some A 5 B 6 C 7-type ternary compounds, BiSeI , BiSI , BiSCl , BiSBr , BiSeBr and SbSeBr , are investigated using the density functional theory and pseudopotential theory under the generalized gradient approximation (GGA). The electronic band structures obtained show that these crystals, except for BiSeI , have an indirect band gap.

scholarly journals The Magnetic Band-Structures of Ordered PtxFe1−x, PtxCo1−x, and PtxNi1−x (x = 0.25, 0.50, and 0.75)

2020 ◽  
Vol 6 (4) ◽  
pp. 61
Author(s):  
Ian Shuttleworth
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
High Symmetry ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Ni Alloys ◽  
Spin Polarized ◽  
Electronic Band Structures

The electronic band structures of the ordered L12 and L10 phases of the PtxM1−x (M = Fe, Co and Ni) alloys were investigated using spin-polarized density functional theory (DFT). The relative contributions of both itinerant (Stoner) and localized magnetism at the high-symmetry k-points were determined and discussed qualitatively. Significant directional effects were identified along the A and R directions of the L10 and L12 alloys, respectively, and are discussed in terms of charge channeling effects.

Electronic band structures of Ge1−xSnx semiconductors: A first-principles density functional theory study

2013 ◽  
Vol 113 (6) ◽  
pp. 063517 ◽  
Author(s):  
Ming-Hsien Lee ◽  
Po-Liang Liu ◽  
Yung-An Hong ◽  
Yen-Ting Chou ◽  
Jia-Yang Hong ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Electronic Band Structures

scholarly journals Влияние размерных эффектов на электронную структуру гексагонального теллурида галлия

2018 ◽  
Vol 60 (9) ◽  
pp. 1645
Author(s):  
А.В. Кособуцкий ◽  
С.Ю. Саркисов
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Bulk Material ◽  
Structural Parameters ◽  
Van Der Waals Interactions ◽  
Electronic Band ◽  
Functional Theory ◽  
Lower Conduction Band ◽  
The Density Functional Theory ◽  
Indirect Band Gap

AbstractUsing methods of the density functional theory, the electronic band structure of a hexagonal modification of the layered GaTe semiconductor has been calculated. The structural parameters of a bulk crystal with the β-polytype symmetry have been determined taking into account van der Waals interactions and agree with experimental data for polycrystalline films within 2%. Estimates for the position of extrema of the upper valence band and the lower conduction band have been obtained with respect to the vacuum level for bulk β-GaTe and for ultrathin plates with the number of elementary layers ranging from 1 to 10, which corresponds to a thickness range of 0.5–8 nm. The calculations demonstrate that hexagonal GaTe is an indirect band gap semiconductor with a forbidden band width varying from 0.8 eV in the bulk material to 2.3 eV in the monolayer.

scholarly journals Structural Analysis, Phase Stability, Electronic Band Structures, and Electric Transport Types of (Bi2)m(Bi2Te3)n by Density Functional Theory Calculations

2021 ◽  
Vol 11 (23) ◽  
pp. 11341
Author(s):  
Sungjin Park ◽  
Byungki Ryu ◽  
SuDong Park
Keyword(s):  
Density Functional Theory ◽  
Phase Stability ◽  
Thermoelectric Materials ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Electric Transport ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Electronic Band Structures

Thermoelectric power generation is a promising candidate for automobile energy harvesting technologies because it is eco-friendly and durable owing to direct power conversion from automobile waste heat. Because Bi−Te systems are well-known thermoelectric materials, research on (Bi2)m(Bi2Te3)n homologous series can aid the development of efficient thermoelectric materials. However, to the best of our knowledge, (Bi2)m(Bi2Te3)n has been studied through experimental synthesis and measurements only. Therefore, we performed density functional theory calculations of nine members of (Bi2)m(Bi2Te3)n to investigate their structure, phase stability, and electronic band structures. From our calculations, although the total energies of all nine phases are slightly higher than their convex hulls, they can be metastable owing to their very small energy differences. The electric transport types of (Bi2)m(Bi2Te3)n do not change regardless of the exchange–correlation functionals, which cause tiny changes in the atomic structures, phase stabilities, and band structures. Additionally, only two phases (Bi8Te9, BiTe) became semimetallic or semiconducting depending on whether spin–orbit interactions were included in our calculations, and the electric transport types of the other phases were unchanged. As a result, it is expected that Bi2Te3, Bi8Te9, and BiTe are candidates for thermoelectric materials for automobile energy harvesting technologies because they are semiconducting.

Surface-dependent band structure variations and bond-level deviations of Cu2O

2021 ◽  
Author(s):  
Chih Shan Tan ◽  
Michael H. Huang
Keyword(s):  
Density Functional Theory ◽  
Band Structure ◽  
Dft Calculations ◽  
Density Functional ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Electronic Band Structures

Density functional theory (DFT) calculations have been performed on 1 to 9 layers of Cu2O (100), (111), and (110) planes to further understand the electronic band structures and the origin...

Size dependent electronic band structures of β- and γ-graphyne nanotubes

RSC Advances ◽  
2015 ◽  
Vol 5 (98) ◽  
pp. 80118-80121 ◽  
Author(s):  
Baotao Kang ◽  
Jong Hun Moon ◽  
Jin Yong Lee
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Band Structures ◽  
Electronic Band ◽  
Functional Theory ◽  
Size Dependent ◽  
Electronic Band Structures

In the present paper, density functional theory calculations have been implemented by using Dmol3 to study the electronic band structures of β-graphyne nanotubes (βGyNTs) and γ-graphyne nanotubes (γGyNTs).

ELECTRONIC BAND STRUCTURES OF InAs(110) AND InAs(110)Bi(1 ML)

1994 ◽  
Vol 01 (04) ◽  
pp. 681-684
Author(s):  
A. UMERSKI ◽  
G.P. SRIVASTAVA
Keyword(s):  
Density Functional ◽  
Local Density ◽  
Experimental Investigations ◽  
Band Structures ◽  
Electronic Band ◽  
Pseudopotential Theory ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Occupied State ◽  
Theoretical Investigations ◽  
Electronic Band Structures

We use a supercell technique with local density functional pseudopotential theory to calculate the self-consistent electronic band structures of InAs (110) with zero and one ordered monolayer coverage of Bi within the Goddard geometry. These systems have recently been the subject of experimental investigations by the McLean group, using angle-resolved photoemission spectroscopy. We are able to analyse the overlayer-induced states in terms of their energies, dispersions, and wave function characters, and our results are compared with the experimentally deduced observations. In addition we contrast our results for these materials with our earlier theoretical investigations of InAs (110) and InP (110) substrates with Bi overlayers. We are therefore able to confirm the experimental observation that the InAs(110)Bi(1 ML) has a relatively flat absorbate induced highest occupied state [in comparison to the GaAs(110)Bi(1 ML) system].

An Investigation of Half-Metallic Ferromagnets Behavior in Hg2CuTi-Type Heusler Alloy Ti2FeAl by Using GGA

2012 ◽  
Vol 535-537 ◽  
pp. 1291-1294 ◽  
Author(s):  
Xiu De Yang ◽  
Bo Wu ◽  
Song Zhang
Keyword(s):  
Density Functional Theory ◽  
Heusler Alloy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Direct Hybridization

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT), the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeAl were investigated. The results reveal that a 100% spin polarization appears at Fermi level (εF) in Ti2FeAl, and is maintained during lattice range of 5.1Å~6.2Å. Ti2FeAl is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV at εF and total magnetic moment of 1μB per unit cell. Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.

scholarly journals Oxygen vacancy and doping atom effect on electronic structure and optical properties of Cd2SnO4

RSC Advances ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 640-646 ◽  
Author(s):  
Mei Tang ◽  
JiaXiang Shang ◽  
Yue Zhang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
La Doped ◽  
Doping Atom ◽  
Atom Effect

The electronic structure and optical properties of oxygen vacancy and La-doped Cd2SnO4 were calculated using the plane-wave-based pseudopotential method based on the density functional theory (DFT) within the generalized gradient approximation (GGA).

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