The Density Functional Study of Electronic Properties for Bismuth Aluminate

2013 ◽  
Vol 873 ◽  
pp. 877-882
Author(s):  
Lian Wei Shan ◽  
Wei Li ◽  
Rui Fang ◽  
Li Min Dong ◽  
Zhi Dong Han ◽  
...  
Keyword(s):  
Band Gap ◽  
Conduction Band ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Study ◽  
Functional Theory ◽  
Interaction Range ◽  
Plane Wave Method ◽  
The Density Functional Theory ◽  
Indirect Band Gap

In this paper, the density functional theory calculations on the electronic structure of BiAlO3 by using ultrasoft pseudopotential plane wave method are carried out. The results show that cubic and trigonal BiAlO3 are indirect band gap semiconductor. And their conduction band is 0.70 and 1.49 eV, respectively. The broadening antibonding interaction range in conduction band is found. It is largely responsible for the decrease in the band gap of cubic BiAlO3. It can be also found that the CB width is obviously narrowed, while the VB width is slightly broadened.

Graphene-Based Sensors for Monitoring Strain

2013 ◽  
Vol 3 (1) ◽  
pp. 74-83
Author(s):  
M. Mirnezhad ◽  
R. Ansari ◽  
H. Rouhi ◽  
M. Faghihnasiri
Keyword(s):  
Fermi Level ◽  
Band Gap ◽  
Strain Distribution ◽  
Density Functional ◽  
Tight Binding ◽  
Density Functional Theory Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Gap Opening

The application of graphene as a nanosensor in measuring strain through its band structure around the Fermi level is investigated in this paper. The mechanical properties of graphene as well as its electronic structure are determined by using the density functional theory calculations within the framework of generalized gradient approximation. In the case of electronic properties, the simulations are applied for symmetrical and asymmetrical strain distributions in elastic range; also the tight-binding approach is implemented to verify the results. It is indicated that the energy band gap does not change with the symmetrical strain distribution but depend on the asymmetric strain distribution, increasing strain leads to band gap opening around the Fermi level.

The Electronic and Structural Properties of 3C-SiC: A First-Principles Study

2014 ◽  
Vol 971-973 ◽  
pp. 208-212 ◽  
Author(s):  
Ying Gao ◽  
Fu Chun Zhang ◽  
Wei Hu Zhang
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
First Principles ◽  
Density Functional ◽  
Energy Splitting ◽  
Functional Theory ◽  
Structure Density ◽  
Indirect Band Gap ◽  
Electronic And Structural Properties

We investigate geometric structure, electronic structure and ground properties of 3C-SiC as obtained form first-principles calculations based on density functional theory with the LDA, GGA, B3LYP and HSE06 method. After comparative analysis of the total energy, band structure, density of states and the bulk modulus, we found that 3C-SiC was an indirect band gap semiconductor, the top of valence band was located at Γ point, and the bottom of conduction band was located at X point. The indirect band gap of 3C-SiC calculated by LDA, GGA, B3LYP and HSE06 was 1.34 eV, 1.44 eV, 2.88 eV and 2.26 eV, respectively. Especially for B3LYP and HSE06 methods which clearly calculated the energy splitting and the energy dispersion of both the top of valence band and the bottom of conduction band was in well agreement with the experimental data. These results will provide theoretical basis for the design and application of SiC materials.

Electronic structure and magnetic ordering in gadolinium-doped AlGaN from LSDA + U calculations

2018 ◽  
Vol 07 (03) ◽  
pp. 1850019 ◽  
Author(s):  
S. Belhachi ◽  
S. Amari ◽  
B. Bouhafs
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Magnetic Ordering ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Indirect Band Gap

We present first-principles calculations of the structural, electronic and magnetic properties of Gd-doped [Formula: see text] based on the density functional theory within [Formula: see text] schemes. It is found that Gd atom favors substituting for Al site. Compared with undoped [Formula: see text], the Gd-doped [Formula: see text] has become an indirect band gap semiconductor of reduced band gap. The magnetic moment [Formula: see text] per molecule mainly comes from Gd ion with little contribution from the Ga, Al and N atoms. It is confirmed that the ferromagnetic configuration is stable for [Formula: see text]. It is found also that there is hybridization between the forbital of the Gd atom and the [Formula: see text] orbital of the N atom.

A comparison study of the structural electronic, elastic and lattice dynamic properties of ZrInAu and ZrSnPt

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sinem Erden Gulebaglan ◽  
Emel Kilit Dogan
Keyword(s):  
Bulk Modulus ◽  
Band Gap ◽  
Density Functional ◽  
Dynamic Properties ◽  
Elastic Stiffness ◽  
Functional Theory ◽  
Density Functional Perturbation Theory ◽  
The Density Functional Theory ◽  
Indirect Band Gap ◽  
First Time

Abstract To estimate the structural, electronic, elastic and dynamic properties of ZrInAu and ZrSnPt compounds, the density functional theory within the general gradient approximation was used. The computed lattice parameters, bulk modulus and the derivation of bulk modulus with respect to pressure were displayed and compared with the theoretical result. The indirect band gap for ZrInAu was found to be 0.48 eV, and for ZrSnPt the indirect band gap was found as 1.01 eV. Elastic stiffness constants, bulk, shear and Young’s module, Poisson’s coefficients and Zener anisotropy factor are calculated. Elastic properties showed that the ZrSnPt compound is more durable than the ZrInAu compound. Phonon distribution curves and density of states were investigated using a density functional perturbation theory. Both ZrInAu and ZrSnPt compounds were demonstrated to be dynamically stable. The results of this study were obtained for the first time in the literature. These results will make an important contribution to the literature.

Graphene-Based Sensors for Monitoring Strain

2014 ◽  
pp. 602-611
Author(s):  
M. Mirnezhad ◽  
R. Ansari ◽  
H. Rouhi ◽  
M. Faghihnasiri
Keyword(s):  
Fermi Level ◽  
Band Gap ◽  
Strain Distribution ◽  
Density Functional ◽  
Tight Binding ◽  
Density Functional Theory Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Gap Opening

The application of graphene as a nanosensor in measuring strain through its band structure around the Fermi level is investigated in this paper. The mechanical properties of graphene as well as its electronic structure are determined by using the density functional theory calculations within the framework of generalized gradient approximation. In the case of electronic properties, the simulations are applied for symmetrical and asymmetrical strain distributions in elastic range; also the tight-binding approach is implemented to verify the results. It is indicated that the energy band gap does not change with the symmetrical strain distribution but depend on the asymmetric strain distribution, increasing strain leads to band gap opening around the Fermi level.

A New Approach for Calculating the Band Gap of Semiconductors within the Density Functional Method

2015 ◽  
Vol 242 ◽  
pp. 434-439 ◽  
Author(s):  
Vasilii E. Gusakov
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
Localized States ◽  
Experimental Accuracy ◽  
Functional Theory ◽  
New Approach ◽  
The Density Functional Theory

Within the framework of the density functional theory, the method was developed to calculate the band gap of semiconductors. We have evaluated the band gap for a number of monoatomic and diatomic semiconductors (Sn, Ge, Si, SiC, GaN, C, BN, AlN). The method gives the band gap of almost experimental accuracy. An important point is the fact that the developed method can be used to calculate both localized states (energy deep levels of defects in crystal), and electronic properties of nanostructures.

Understanding the advantage of hexagonal WO3 as an efficient photoanode for solar water splitting: a first-principles perspective

2016 ◽  
Vol 4 (29) ◽  
pp. 11498-11506 ◽  
Author(s):  
Taehun Lee ◽  
Yonghyuk Lee ◽  
Woosun Jang ◽  
Aloysius Soon
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Water Splitting ◽  
Anode Material ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Good Alternative ◽  
Functional Theory ◽  
Solar Water Splitting

Using first-principles density-functional theory calculations, we investigate the advantage of using h-WO3 (and its surfaces) over the larger band gap γ-WO3 phase for the anode in water splitting. We demonstrate that h-WO3 is a good alternative anode material for optimal water splitting efficiencies.

scholarly journals Synthesis, Mass Spectroscopy Detection, and Density Functional Theory Investigations of the Gd Endohedral Complexes of C82 Fullerenols

Computation ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 58
Author(s):  
Anastasia A. Shakirova ◽  
Felix N. Tomilin ◽  
Vladimir A. Pomogaev ◽  
Natalia G. Vnukova ◽  
Grigory N. Churilov ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Mass Spectrometry Analysis ◽  
Structure And Properties ◽  
Functional Theory ◽  
Endohedral Complexes ◽  
Spectrometry Analysis ◽  
The Density Functional Theory ◽  
Atomic And Electronic Structure

Gd endohedral complexes of C82 fullerenols were synthesized and mass spectrometry analysis of their composition was carried out. It was established that the synthesis yields a series of fullerenols Gd@C82Ox(OH)y (x = 0, 3; y = 8, 16, 24, 36, 44). The atomic and electronic structure and properties of the synthesized fullerenols were investigated using the density functional theory calculations. It was shown that the presence of endohedral gadolinium increases the reactivity of fullerenols. It is proposed that the high-spin endohedral fullerenols are promising candidates for application in magnetic resonance imaging.

scholarly journals Effect of Yb Concentration on the Structural, Magnetic and Optoelectronic Properties of Yb Doped ZnO: First Principles Calculation

2021 ◽  
Author(s):  
Mohamed Achehboune ◽  
Mohammed Khenfouch ◽  
Issam Boukhoubza ◽  
Issam Derkaoui ◽  
Bakang Moses Mothudi ◽  
...  
Keyword(s):  
Band Gap ◽  
Conduction Band ◽  
Density Functional ◽  
Blue Shift ◽  
First Principles Calculation ◽  
Theoretical Research ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Doped Zno ◽  
Good Agreement

Abstract Density functional theory-based investigation of the electronic, magnetic, and optical characteristics in pure and ytterbium (Yb) doped ZnO has been carried out by the plane-wave pseudopotential technique with generalized gradient approximation. The calculated lattice parameters and band gap of pure ZnO are in good agreement with the experimental results. The energy band-gap increases with the increase of Yb concentration. The Fermi level moves upward into the conduction band after doping with Yb, which shows the properties of an n-type se miconductor. New defects were created in the band-gap near the conduction band attributed to the Yb-4f states. The magnetic properties of ZnO were found to be affected by Yb doping; ferromagnetic property was observed for 4.17% Yb due to spin polarization of Yb-4f electrons. The calculated optical properties imply that Yb doped causes a blue shift of the absorption peaks, significantly enhances the absorption of the visible light, and the blue shift of the reflectivity spectrum was observed. Besides, a better transmittance of approximately 88% was observed for 4.17% Yb doped ZnO system. The refractive index and the extinction coefficient were observed to decrease as the Yb dopant concentration increased. As a result, we believe that our findings will be useful in understanding the doping impact in ZnO and will motivate further theoretical research.

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