Electronic Energy Bands in γ-InSe with and without Intercalated Lithium

1990 ◽  
Vol 210 ◽  
Author(s):  
P. Gomes Da Costa ◽  
M. Balkanski ◽  
R. F. WALLIS
Keyword(s):  
Lithium Atom ◽  
Electronic Band Structure ◽  
Tight Binding ◽  
Electronic Energy ◽  
Band Gaps ◽  
Energy Bands ◽  
Energy Position ◽  
Electronic Band ◽  
Direct Band ◽  
Electronic Energy Bands

AbstractThe effect of intercalated lithium on the electronic band structure of the γ-polytype of InSe has been investigated using a tight-binding method. The energy bands of the pure polytype were calculated and the results compared with previous work. The modifications of the energy bands produced by the introduction of one lithium atom per unit cell were calculated for the lowest potential energy position of the lithium atom in the Van der Waals gap between layers. The results for the changes in the smallest and next-to-smallest direct band gaps are compared with experimental data. An interpretation of a photoluminescence peak produced by lithium intercalation is given.

The Spin-Resolved Electronic Band Structure of Cadmium Oxide Doped with Transition Elements

2013 ◽  
Vol 200 ◽  
pp. 123-128 ◽  
Author(s):  
Stepan Syrotyuk ◽  
Vira Shved
Keyword(s):  
Electronic Band Structure ◽  
Cadmium Oxide ◽  
Transition Element ◽  
Electronic Energy ◽  
Total Density ◽  
Transition Elements ◽  
Energy Bands ◽  
Strong Electron ◽  
Electronic Band ◽  
Electronic Energy Bands

The spin-resolved electronic energy bands and partial and total density of states of cadmium oxide doped with Sc, Ti and Cr have been evaluated by means of the ABINIT code. The strong electron correlations of Cd 4d and transition element 3d states have been taken into account. It was found that the CdScO and CdTiO crystals are paramagnetic and CdCrO shows the ferromagnetic ordering.

scholarly journals First Principles Study of Copper Sulfides (for Applications as Photoconductors)

2012 ◽  
Vol 730-732 ◽  
pp. 111-116 ◽  
Author(s):  
Jorge A. Ferreira ◽  
M. Helena Braga
Keyword(s):  
First Principles ◽  
Electronic Band Structure ◽  
Band Gaps ◽  
Solid Solution Series ◽  
Electronic Band ◽  
Copper Sulfides ◽  
Direct Band Gap ◽  
Photovoltaic Materials ◽  
Complete Solid Solution ◽  
Direct Band

The Tetrahedrite’s family constitutes a complete solid-solution series, and is among the most frequent complex sulfides in Nature. This kind of structure can be generically expressed by the composition, Cu12Sb4S13. We have calculated the electronic band structure of Cu12Sb4S13 and Ag6Cu6Sb4S13 (with band gaps of 1.24 and 1.20 eV, respectively) to demonstrate that different elements occupying certain sites of the crystal structure will make a difference in what concerns the conduction process in Tetrahedrites. We will use this effect and ab initio calculations to show that the electronic properties of these compounds make them promising candidates as solar cells photovoltaic materials since not only they possess a direct band gap but their energy falls within the range of energies of photovoltaics. Moreover, we can optimize these properties by doping and substituting ions furthermore. Mechanical properties were also calculated for both compounds and will be compared.

ELECTRONIC BAND STRUCTURE OF CARBON NANOTUBES WITH QUINOID STRUCTURE

2013 ◽  
Vol 27 (25) ◽  
pp. 1350179
Author(s):  
NGUYEN NGOC HIEU ◽  
NGUYEN PHAM QUYNH ANH
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Band Structure ◽  
Electronic Band Structure ◽  
Tight Binding ◽  
Electronic Energy ◽  
Electronic Band ◽  
Tight Binding Approximation ◽  
Quinoid Structure ◽  
Structure Of Carbon Nanotubes

In this paper, we fully describe the geometry of atomic structure of carbon nanotube with quinoid structure. Electronic energy band structure of carbon nanotubes with quinoid structure is studied by tight-binding approximation. In the presence of bond alternation, calculations show that only armchair (n, n) carbon nanotube (without twisting) remains metallic and zigzag (3ν - 1, -3ν + 1) CNT becomes metallic at the critical elongation. Effect of deformation on the change of band gap is also calculated and discussed.

ON THE COUPLING BETWEEN ELECTRONS AND SOFT-MODE PHONONS IN La2CuO4

1990 ◽  
Vol 04 (07) ◽  
pp. 489-496 ◽  
Author(s):  
Z. K. PETRU ◽  
N. M. PLAKIDA
Keyword(s):  
Fermi Energy ◽  
Soft Mode ◽  
Tight Binding ◽  
Electronic Energy ◽  
Tight Binding Model ◽  
Energy Bands ◽  
Phonon Modes ◽  
Binding Model ◽  
Bond Bending ◽  
Electronic Energy Bands

An interaction between soft bond-bending phonon modes and localized 3d – 2p electrons is considered. Its strength is estimated to be of the order of 1 eV/Å. By means of the tight-binding model, the electronic energy bands of La 2 CuO 4 are calculated. It is explicitly shown that a tetragonal to orthorhombic transition does not open a gap at the Fermi energy.

scholarly journals The recurrent relations for the electronic band structure of the multilayer graphene

2018 ◽  
Vol 474 (2220) ◽  
pp. 20180439 ◽  
Author(s):  
V. N. Davydov
Keyword(s):  
Band Structure ◽  
Electronic Band Structure ◽  
Electronic Energy ◽  
Multilayer Graphene ◽  
Energy Bands ◽  
Linear Dispersion ◽  
Electronic Band ◽  
Tight Binding Approximation ◽  
Number Of Layers ◽  
Recurrent Relations

The structure of the electronic energy bands for stacked multilayer graphene is developed using the tight-binding approximation (TBA). The spectra of the Dirac electrons are investigated in vicinity of the Brillouin zone minima. The electron energy dependence on quasi-momentum is established for an arbitrary number of the graphene layers for multilayer graphene having even number of layers N  = 2 n , ( n  = 2, 3, 4, …) with the Bernal stacking ABAB … AB; or for odd number of layers N  = 2 n  + 1, ( n  = 1, 2, 3, …) with stacking ABAB … A. It is shown that four non-degenerate energy branches of the electronic energy spectrum are present for any number of layers. Degeneracy is considered of graphene-like energy branches with linear dispersion law. Dependences of such branches number and their degeneracy are found on number of layers. The recurrent relations are obtained for the electronic band structure of the stacked ABA…, ABC… and AAA… multilayer graphene. The flat electronic bands are obtained for ABC-stacked multilayer graphene near the K -point at the Fermi level. Such an approach may be useful in the study of multivarious aspects of graphene's physics and nanotechnologies. Also paper gives new hints for deeper studies of graphite intercalation compounds.

FIRST PRINCIPLE CALCULATION OF ELECTRONIC BAND STRUCTURE AND OPTICAL PROPERTIES OF KIO3

2009 ◽  
Vol 23 (10) ◽  
pp. 2405-2412
Author(s):  
HARUN AKKUS ◽  
BAHATTIN ERDINC
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Functional Methods ◽  
A Value ◽  
Direct Band

The electronic band structure and optical properties of the ferroelectric single crystal KIO 3 have been investigated using the density functional methods. The calculated band structure for KIO 3 evidences that the crystal has a direct band gap with a value of 2.83 eV. The structural optimization has been performed. The real and imaginary parts of dielectric function, energy-loss function for volume and surface, and refractive index are calculated along the crystallographic axes.

scholarly journals Structural Optimization, Electronic Band Structure, Mechanical and Thermodynamics Properties of Fe3Al

2021 ◽  
pp. 1-11
Author(s):  
I. S. Okunzuwa ◽  
E. Aigbekaen Eddy
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Plane Waves ◽  
State Density ◽  
Structural Parameter ◽  
Mechanical And Thermal Properties ◽  
Energy Bands ◽  
Electronic Band ◽  
Salt Structure ◽  
Quantum Espresso

We calculated the structural, electronic, mechanical and thermal properties of Fe3Al semiconducting using Quantum ESPRESSO, an open source first principles code based on density-functional theory, plane waves, and pseudopotentials. Structural parameter results (equilibrium lattice parameters, bulk modulus and its derivative pressure) have been reported. The underestimated band gap is obtained along with higher state density and energy bands around the fermi level. Mechanical properties of the rock-salt structure of Fe3Al, such as, shear modulus (G), Young’s modulus (E), and Poisson’s ratio () were investigated. The thermodynamic parameters are also present. The results are in good agreement with the available experimental and other theoretical results.

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