First-principles calculation of defect formation energies and electronic properties in stannate pyrochlores

2008 ◽  
Vol 104 (9) ◽  
pp. 093702 ◽  
Author(s):  
Z. J. Chen ◽  
H. Y. Xiao ◽  
X. T. Zu ◽  
F. Gao
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Defect Formation ◽  
First Principles Calculation ◽  
Formation Energies

Structures and Electronic Properties of Graphene with Vacancy Defects

2014 ◽  
Vol 1658 ◽  
Author(s):  
J. Sugimoto ◽  
K. Shintani
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
First Principles Calculation ◽  
Band Structures ◽  
Electronic Band ◽  
Vacancy Defects ◽  
Electronic Band Structures ◽  
Formation Energies

ABSTRACTThe structures and electronic properties of graphene with defects consisting of one to six atomic vacancies are investigated using first-principles calculation. All of the geometrically possible initial structures of a movacancy or a multivacancy in graphene are equilibrated. The formation energies and electronic band structures for the equilibrated defective structures are calculated. It is suggested non-zero bandgaps may be induced in graphene by introducing some types of monovacancy or multivacancy although further checks regarding supercell size are necessary to ensure the present results.

First-principles calculation of structural and energetic properties for A2Ti2O7 (A = Lu, Er, Y, Gd, Sm, Nd, La)

2009 ◽  
Vol 24 (4) ◽  
pp. 1335-1341 ◽  
Author(s):  
Z.L. Zhang ◽  
H.Y. Xiao ◽  
X.T. Zu ◽  
Fei Gao ◽  
W.J. Weber
Keyword(s):  
First Principles ◽  
Radiation Resistance ◽  
Formation Energy ◽  
Defect Formation ◽  
Band Gaps ◽  
First Principles Calculation ◽  
Energetic Properties ◽  
Cation Radius ◽  
A Site ◽  
Formation Energies

A first-principles method was used to investigate the structural and energetic properties for A2Ti2O7 (A = Lu, Er, Y, Gd, Sm, Nd, La), including the formation energies of the cation antisite-pair, the anion Frenkel pair that defines anion-disorder, and the coupled cation antisite-pair/anion-Frenkel. It is proposed that the 〈A–O48f〉 interaction may have more significant influence on the radiation resistance behavior of titanate pyrochlores, although the 〈Ti–O48f〉 interactions are relatively stronger than the 〈A–O48f〉 interactions. It was found that the defect formation energies are not simple functions of the A-site cation radii. The formation energy of the cation antisite-pair increases continuously as the A-site cation varies from Lu to Gd, and then decreases continuously with the variation of the A-site cation from Gd to La, in excellent agreement with the radiation-resistance trend of the titanate pyrochlores. The band gaps in these pyrochlores were also measured, and the band gap widths changed continuously with cation radius.

A First-Principles Calculation of Electronic Properties of LiNH2 and NaNH2

2018 ◽  
Vol 59 (6) ◽  
pp. 1251-1257
Author(s):  
E. B. Kaizer ◽  
N. G. Kravchenko ◽  
A. S. Poplavnoi
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
First Principles Calculation

New Pt-based Superalloy System Designed from First Principles

2008 ◽  
Vol 1128 ◽  
Author(s):  
Vsevolod I. Razumovskiy ◽  
Eyvaz I. Isaev ◽  
Andrei V. Ruban ◽  
Pavel A. Korzhavyi
Keyword(s):  
Elastic Properties ◽  
First Principles ◽  
Defect Formation ◽  
Alloy System ◽  
First Principles Calculations ◽  
Phonon Spectra ◽  
Ultrahigh Temperature ◽  
New Generation ◽  
Formation Energies ◽  
Temperature Applications

AbstractPt-Sc alloys with the γ-γ′ microstructure are proposed as a basis for a new generation of Pt-based superalloys for ultrahigh-temperature applications. This alloy system was identified on the basis of first-principles calculations. Here we discuss the prospects of the Pt-Sc alloy system on the basis of calculated elastic properties, phonon spectra, and defect formation energies.

scholarly journals Structural and Electronic Properties of Orthorhombic Phase Bi2Se3 Based On First-Principles Study

2019 ◽  
Vol 16 (2) ◽  
pp. 77 ◽  
Author(s):  
Muhammad Zamir Mohyedin ◽  
Afiq Radzwan ◽  
Mohammad Fariz Mohamad Taib ◽  
Rosnah Zakaria ◽  
Nor Kartini Jaafar ◽  
...  
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Computer Code ◽  
First Principles Calculation ◽  
Generalized Gradient ◽  
Exchange Correlation ◽  
Percentage Difference ◽  
Structural And Electronic Properties

Bi2Se3 is one of the promising materials in thermoelectric devices and very useful out of environmental concern due to its efficiency to perform at room temperature. Based on the first-principles calculation of density functional theory (DFT) by using CASTEP computer code, structural and electronic properties of Bi2Se3 were investigated. The calculation is conducted within the exchange-correlation of local density approximation (LDA) and generalized gradient approximation within the revision of Perdew-Burke-Ernzerhof (GGA-PBE) functional. It was found that the results are consistent with previous works of theoretical study with small percentage difference. LDA exchange-correlation functional method is more accurate and have a better agreement than GGA-PBE to describe the structural properties of Bi2Se3 which consist of lattice parameters. LDA functional also shown more accurate electronic structure of Bi2Se3 that consist of band structure and density of states (DOS) which consistent with most previous theoretical works with small percentage difference. This study proves the reliability of CASTEP computer code and show LDA exchange-correlation functional is more accurate in describing the nature of Bi2Se3 compared to the other functionals.

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