First-Principles Calculation of Electronic Structure of the Cu–Doped Pyrite FeS2

2013 ◽  
Vol 652-654 ◽  
pp. 590-593 ◽  
Author(s):  
Jian Ling Fan ◽  
Sen Kai Lu
Keyword(s):  
First Principles ◽  
Weak Field ◽  
First Principles Calculation ◽  
Structure Stability ◽  
First Principle ◽  
Density Of State ◽  
Covalent Character ◽  
Bottom Part ◽  
Tetrahedral Environment ◽  
Pseudo Potential

Structure stability and electronic properties of Cu-doped FeS2 were studied using the first principle calculations based on plane wave pseudo-potential theory. The calculated results revealed that the band-gap Eg of Cu-doped FeS2was 0.47 eV. The valence band of the density of state (DOS) was mostly due to the Cu 3d and S p orbitals. The bottom part of conduction band was mostly due to the Fe 3d orbitals. The calculated covalent character of the Fe–S bonds gave large delocalization of the spin resulting in smaller values. The Cu, Fe and S had the spin compensated leading to configuration s0.47 p0.61d9.78, Fe s0.27p0.58d7.03, S s1.83p4.23, respectively. The tetrahedral environment of the Fe and Cu and the relatively weak field of the S2− ligand were consistent to the Fe3+ and Cu+.

First Principles Calculation of Geometrical and Electronic Structure of Semiconductor Fe1-xMnxSi2

2011 ◽  
Vol 213 ◽  
pp. 483-486
Author(s):  
Fang Gui ◽  
Shi Yun Zhou ◽  
Wan Jun Yan ◽  
Chun Hong Zhang ◽  
Xiao Tian Guo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Function Theory ◽  
Density Function Theory ◽  
First Principles Calculation ◽  
First Principle ◽  
Substitutional Doping ◽  
Pseudo Potential ◽  
Mn Concentrations

The electronic structure and optical properties of Fe1-xMnxSi2 have been studied using the first principle plane-wave pseudo-potential based on the density function theory. Substitutional doping is considered with Mn concentrations of x=0.0625, 0.125, 0.1875 and 0.25, respectively. The calculated results show that the volume of β-FeSi2 increase and the band gap increase with increasing of Mn.

Structural Stability and Electronic Properties of Fe-Doped B13C2: First-Principles Investigation

2013 ◽  
Vol 652-654 ◽  
pp. 344-347
Author(s):  
Yi Wei Qin ◽  
Sen Kai Lu
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electronic Properties ◽  
First Principles ◽  
Structural Unit ◽  
Covalent Bond ◽  
Structure Stability ◽  
First Principle ◽  
First Principle Calculations ◽  
Pseudo Potential

Structure stability and electronic properties of Fe-doped boron carbides (B13C2) were studied using the first principle calculations based on plane wave pseudo-potential theory. The calculated results showed that the Fe-doped boron carbide representative stable structural is Fe substituting C atom on the end of chain C-B-C. The band structure and density of states (DOS) indicated that the coexistence of [C-B-Fe] ε+-[B11C] ε- structural unit made electrical conductivity increased. As the covalent bond of Fe-B was weaker than those of B-B and B-C, the thermal conductivity decreased for Fe-doped B13C2, thermoelectric property of Fe-doped boron carbides has been improved.

Effect of Alloying Elements V, Cr and Ni on the Electronic Structure and Mechanical Properties of FeAl from First-Principles Calculation

2014 ◽  
Vol 887-888 ◽  
pp. 378-383 ◽  
Author(s):  
Yu Chen ◽  
Zheng Jun Yao ◽  
Ping Ze Zhang ◽  
Dong Bo Wei ◽  
Xi Xi Luo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electronic Structure ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Valence Bond ◽  
Ternary Alloys ◽  
First Principles Calculation ◽  
Structure Stability ◽  
Alloying Element

The structure stability, mechanical properties and electronic structures of B2 phase FeAl intermetallic compounds and FeAl ternary alloys containing V, Cr or Ni were investigated using first-principles density functional theory calculations. Several models are established. The total energies, cohesive energies, lattice constants, elastic constants, density of states, and the charge densities of Fe8Al8 and Fe8XAl7 ( X=V, Cr, Ni ) are calculated. The stable crystal structures of alloy systems are determined due to the cohesive energy results. The calculated lattice contants of Fe-Al-X ( X= V, Cr, Ni) were found to be related to the atomic radii of the alloy elements. The calculation and analysis of the elastic constants showed that ductility of FeAl alloys was improved by the addition of V, Cr or Ni, the improvement was the highest when Cr was used. The order of the ductility was as follows: Fe8CrAl7 > Fe8NiAl7 > Fe8VAl7 > Fe8Al8. The results of electronic structure analysis showed that FeAl were brittle, mainly due to the orbital hybridization of the s, p and d state electron of Fe and the s and p state electrons of Al, showing typical characteristics of a valence bond. Micro-mechanism for improving ductility of FeAl is that d orbital electron of alloying element is maily involved in hybridization of FeAl, alloying element V, Cr and Ni decrease the directional property in bonding of FeAl.

First Principle Study of the Electronic Structure of Gd2SrAl2O7

2010 ◽  
Vol 434-435 ◽  
pp. 448-450
Author(s):  
J. Feng ◽  
Wei Pan ◽  
B. Xiao ◽  
Rui Fen Wu ◽  
Chun Lei Wan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
First Principle ◽  
Ionic Bond ◽  
Covalent Character ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
A Charge

The ground state electronic structure of Gd2SrAl2O7 are calculated using first principles, we found that only the Density functional theory (DFT) + U can correctly describe the Gd2SrAl2O7 as a charge-transfer type insulator. Gd-O and Al-O bonds have strong covalent character and Sr-O is a perfect ionic bond. The band gap of Gd2SrAl2O7is 3.9 eV, and it is opened due the large U correction for 4f orbit.

Theoretical Investigation on Microstructure of the Novel 24R-Type LPSO Phase in Mg97Zn1Y2 Alloy

2011 ◽  
Vol 233-235 ◽  
pp. 2359-2366
Author(s):  
Ping Ying Tang ◽  
Meng Xue Zeng ◽  
Dong Lin Li ◽  
Bi Yu Tang ◽  
Li Ming Peng ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Stacking Fault ◽  
First Principles Calculation ◽  
The Novel ◽  
Ordered Structure ◽  
Density Of State ◽  
Electronic Density ◽  
Functional Theory ◽  
Long Period

The first-principles calculation based on density functional theory has been carried out to study the microstructural feature of the novel 24R-type long period stacking ordered structure in Mg97Zn1Y2alloy. The lattice positions of the Y and Zn atoms are determined theoretically, it is shown that the additive atoms are firstly enriched in the stacking fault layers at the two ends, a small amount are distributed in the interior stacking fault layers of the structure. And the arrangement of these Y and Zn atoms trends to be along the diagonal line of the unit cell. The structural stability is analyzed and the electronic density of state is discussed as well as.

FIRST-PRINCIPLES CALCULATION OF LEAD-FREE PEROVSKITE SnTiO3

2013 ◽  
Vol 27 (24) ◽  
pp. 1350144 ◽  
Author(s):  
HONGJUN YE ◽  
RUIZHI ZHANG ◽  
DAWEI WANG ◽  
YU CUI ◽  
JIE WEI ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Formation Energy ◽  
Piezoelectric Materials ◽  
First Principles Calculation ◽  
Lead Free ◽  
Structure Stability ◽  
Functional Theory ◽  
Phonon Spectra ◽  
Sn Substitution

The phonon spectra, band structure and density of states of cubic perovskite SnTiO 3 were investigated using first-principles density functional theory (DFT) computation. The potential energy curves of cations displacement and the formation energy of Sn substitution to B-site were calculated to estimate the structure stability. The results indicate that perovskite SnTiO 3 is a promising ferroelectric end member for lead-free piezoelectric materials and applications.

scholarly journals The first principle calculation of improving p-type characteristics of BxAl1-xN

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhengqian Lu ◽  
Fang Wang ◽  
Yuhuai Liu
Keyword(s):  
First Principles ◽  
Hole Concentration ◽  
First Principles Calculation ◽  
Semiconductor Materials ◽  
First Principle ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Inhibition Effect ◽  
Deep Ultraviolet ◽  
P Type

AbstractAlN is one of the third-generation semiconductor materials with wide application prospects due to its 6.2 eV band gap. In the application of semiconductor deep ultraviolet lasers, progress is slow due to the difficulty in obtaining p-type AlN with good performance. In this paper, the commonly used way of Mg directly as AlN dopant is abandoned, the inhibition effect of the B component on self-compensation of AlN crystal was studied. The improvement of self-compensation performance of AlN crystal by B component is studied by first principles calculation. The results show that the addition of B component can increase the hole concentration of AlN, which is conducive to the formation of p-type AlN.

scholarly journals Insight into the surface activity of defect structure in α-MnO2 nanorod: first-principles research

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pengsen Zhao ◽  
Guifa Li ◽  
Haizhong Zheng ◽  
Shiqiang Lu ◽  
Ping Peng
Keyword(s):  
Electrostatic Potential ◽  
First Principles ◽  
Defect Structure ◽  
Dipole Moments ◽  
Chemical Activity ◽  
First Principles Calculation ◽  
Density Of State ◽  
Electronic Density ◽  
Bulk Surface ◽  
Excellent Chemical

AbstractThe contribution of defect structure to the catalytic property of α-MnO2 nanorod still keeps mysterious right now. Using microfacet models representing defect structure and bulk models with high Miller index, several parameters, such as cohesive energy, surface energy, density of state, electrostatic potential, et al., have been used to investigate the internal mechanism of their chemical activities by first-principles calculation. The results show that the trend in surface energies of microfacet models follows as Esurface[(112 × 211)] > Esurface[(110 × 211)] > Esurface[(100 × 211)] > Esurface[(111 × 211)] > Esurface[(112 × 112)] > Esurface[(111 × 112)], wherein all of them are larger than that of bulk models. So the chemical activity of defect structure is much more powerful than that of bulk surface. Deep researches on electronic structure show that the excellent chemical activity of microfacet structure has larger value in dipole moments and electrostatic potential than that of bulk surface layer. And the microfacet models possess much more peaks of valent electrons in deformantion electronic density and molecular orbital. Density of state indicates that the excellent chemical activity of defect structure comes from their proper hybridization in p and d orbitals.

scholarly journals First-principles Calculation of the Electronic Structure and Optical Properties of ZnO Co-doped with Nb and Ta

2019 ◽  
Vol 25 (3) ◽  
pp. 238-245 ◽  
Author(s):  
Jinpeng WANG ◽  
Tao SHEN ◽  
Hongchen LIU
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculation ◽  
Ultraviolet Region ◽  
First Principle ◽  
Co Doping ◽  
First Principle Calculations ◽  
Function Loss ◽  
Co Doped

First-principle calculations have been performed to investigate the electronic structure and optical properties of ZnO co-doped with Nb and Ta. The three doping structures are set to: Zn0.9375Nb0.0625O, Zn0.9375Ta0.0625O and Zn0.875Nb0.0625Ta0.0625O. The experiments show that co-doping with Nb and Ta narrows the band gap. And it causes the Fermi level to shift upwards and enter the conduction band, while enhancing the conductivity of the doped system. In addition, it has been determined that the dielectric imaginary part of the dopant system is larger than that of the pure ZnO in the low energy region. The absorption side of the dopant system, on the other hand, exhibits a redshift. Furthermore, the transmittance of the ultraviolet region is significantly increased, and the function loss spectrum appears to redshift. This will provide a good theoretical basis for the study and the applications of photoelectric materials co-doped with Nb and Ta. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19956

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