scholarly journals Electronic Structure of Substitutionally Disordered Alloys: Direct Configurational Averaging

1992 ◽  
Vol 278 ◽  
Author(s):  
C. Wolverton ◽  
D. De Fontaine ◽  
H. Dreysse ◽  
G. Ceder
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Local Density ◽  
Tight Binding ◽  
Ternary Alloys ◽  
Orbital Method ◽  
Thermodynamic Quantities ◽  
Local Density Of States ◽  
Disordered Alloys ◽  
Effective Cluster

AbstractThe method of direct configurational averaging (DCA) has been proposed to study the electronic structure of disordered alloys. Local density of states and band structure energies are obtained by averaging over a small number of configrations within a tight-binding Hamiltonian. Effective cluster interactions, the driving quantities for ordering in solids, are computed for various alloys using a tight-binding form of the linearized muffin-tin orbital method (TB-LMTO). The DCA calculations are used to determine various energetic and thermodynamic quantities for binary and ternary alloys.

Electronic band structure of silver low-index surfaces: a tight-binding study

2020 ◽  
Vol 98 (5) ◽  
pp. 488-496
Author(s):  
H.J. Herrera-Suárez ◽  
A. Rubio-Ponce ◽  
D. Olguín
Keyword(s):  
Band Structure ◽  
Density Of States ◽  
Electronic Band Structure ◽  
Local Density ◽  
Tight Binding ◽  
Theoretical Data ◽  
Binding Study ◽  
Local Density Of States ◽  
Electronic Band ◽  
Tight Binding Method

We studied the electronic band structure and corresponding local density of states of low-index fcc Ag surfaces (100), (110), and (111) by using the empirical tight-binding method in the framework of the Surface Green’s Function Matching formalism. The energy values for different surface and resonance states are reported and a comparison with the available experimental and theoretical data is also done.

Electronic Structures at Metal/Alumina Interfaces

1990 ◽  
Vol 193 ◽  
Author(s):  
M. Kohyama ◽  
S. Kose ◽  
M. Kinoshita ◽  
R. Yamamoto
Keyword(s):  
Electronic Structure ◽  
Chemical Bond ◽  
Photoelectron Spectroscopy ◽  
Electronic Structures ◽  
Local Density ◽  
Tight Binding ◽  
Theoretical Method ◽  
Local Density Of States ◽  
Spectroscopy Study ◽  
Metal Atoms

ABSTRACTThe electronic structure of the interface between α-Al2O3(0001) and Nb layers has been calculated using the empirical tight-binding method and the slab model. It has been shown that a direct chemical bond of both covalent and ionic characters can be established at the interface between the surface O atoms of α-Al2O3 and the Nb atoms, which is consistent with the recent photoelectron spectroscopy study. General trends of the electronic structure and chemical bond at the interfaces between α-Al2O3.(0001) and a series of 4d transition metals have been examined using the same theoretical method. In all cases, there exist similar interactions between the surface O atoms and the metal atoms, and it has been observed that the occupancy in the portion of the antibonding peaks of the local density of states at the interface increases as the atomic number of the transition metal increases.

ELECTRONIC STRUCTURE OF STRAINED VANADIUM OVERLAYERS ON W(100) AND Ta(100)

1996 ◽  
Vol 03 (04) ◽  
pp. 1505-1509 ◽  
Author(s):  
R. DE COSS
Keyword(s):  
Electronic Structure ◽  
Density Of States ◽  
Lattice Mismatch ◽  
Local Density ◽  
Tight Binding ◽  
Local Density Of States ◽  
Tight Binding Approximation ◽  
Surface Electronic Structure ◽  
Topmost Layer ◽  
Surface Green Function

We study the role of hybridization and overlayer–substrate lattice mismatch in determining the surface electronic structure of strained V monolayers and bilayers on W(100) and Ta(100). The local density of states is calculated in the tight-binding approximation within the surface-Green-function-matching formalism. For one monolayer of V on W(100) and Ta(100), the strong monolayer–substrate 3d–5d hybridization determines the features of the surface local density of states, with essentially no differences between 1V/W(100) and 1V/Ta(100). For the bilayer we find that the electronic structure of the topmost layer depends strongly on the lattice mismatch between overlayer and substrate. In particular, we find that the surface local density of states at the Fermi level in 2V/Ta(100) is 69% higher than in 1V/Ta(100); the lattice mismatch between bulk constants of V and Ta is 9.0%. These results indicate that strain induces strong band narrowing in vanadium overlayers on transition metals, despite the large overlayer–substrate hybridization, but depends critically on the film thickness.

ENERGY GAP DEPENDENCE ON ANION CONCENTRATION FOR GaxIn1-xAsyP1-y QUATERNARY ALLOY BY RECURSION METHOD

2004 ◽  
Vol 18 (18) ◽  
pp. 955-962
Author(s):  
MUSA EL-HASAN ◽  
REZEK ESTATIEH
Keyword(s):  
Density Of States ◽  
Energy Gap ◽  
Local Density ◽  
Tight Binding ◽  
Quaternary Alloy ◽  
Average Density ◽  
Local Density Of States ◽  
Recursion Method ◽  
Orbital Decomposition ◽  
Lattice Matched

Three terminators have been tested, square root terminator, quadreture terminator and linear terminator, it was found that the linear terminator is the best, so it was used in calculating local density of states (LDOS) and it's orbital decomposition, alloy average density of states, and energy gap for different anion concentrations for InP lattice matched alloy. The results were compared with our previous calculations of (LDOS), and results from other methods. Energy gap was compared with experimental measurements. A five orbital sp3s* per atom model was used in the tight-binding representation of the Hamiltonian.

scholarly journals Influence of water on the properties of an Au/Mpy/Pd metal/molecule/metal junction

2011 ◽  
Vol 2 ◽  
pp. 384-393 ◽  
Author(s):  
Jan Kučera ◽  
Axel Groß
Keyword(s):  
Electronic Structure ◽  
Local Density ◽  
Bilayer Structure ◽  
Local Density Of States ◽  
Self Assembled Monolayer ◽  
Bulk Metal ◽  
Strong Bond ◽  
Nanoelectronic Devices ◽  
Hexagonal Ice ◽  
Influence Of Water

The geometric and electronic structure of the metal–molecule interface in metal/molecule/metal junctions is of great interest since it affects the functionality of such units in possible nanoelectronic devices. We have investigated the interaction between water and a palladium monolayer of a Au(111)/4-mercaptopyridine/Pd junction by means of DFT calculations. A relatively strong bond between water and the palladium monolayer of the Au/Mpy/Pd complex is observed via a one-fold bond between the oxygen atom of the water molecule and a Pd atom. An isolated H2O molecule adsorbs preferentially in a flat-lying geometry on top of a palladium atom that is at the same time also bound to the nitrogen atom of a Mpy molecule of the underlying self-assembled monolayer. The electronic structure of these Pd atoms is considerably modified which is reflected in a reduced local density of states at the Fermi energy. At higher coverages, water can be arranged in a hexagonal ice-like bilayer structure in analogy to water on bulk metal surfaces, but with a much stronger binding which is dominated by O–Pd bonds.

Analysis of the structure of the surface local density of states at the Fermi level: an application of the surface Green function matching method

1989 ◽  
Vol 67 (9) ◽  
pp. 841-844 ◽  
Author(s):  
R. Baquero ◽  
L. Quiroga ◽  
A. Camacho
Keyword(s):  
Charge Transfer ◽  
Local Density ◽  
Tight Binding ◽  
Ferromagnetic Behavior ◽  
Local Density Of States ◽  
Matching Method ◽  
Full Agreement ◽  
Surface Band ◽  
Surface Green Function ◽  
Theory And Experiment

We use a tight-binding description of the bands of bulk vanadium to set a surface-band structure. We show that knowledge of the s–d charge transfer in the surface layer is very important to be able to reproduce the ferromagnetic behavior of the (100) vanadium surface. We use the surface Stoner criterion of Allan to determine the acceptable values for the s–d charge transfer. There is no full agreement between theory and experiment on the magnetic properties of (100) vanadium at present.

Local Electronic Structure and Short-Range Order in a Computer Simulated Amorphous Metal

1991 ◽  
Vol 02 (01) ◽  
pp. 232-237 ◽  
Author(s):  
A.Ya. BELENKII ◽  
M.A. FRADKIN
Keyword(s):  
Electronic Structure ◽  
Short Range ◽  
Short Range Order ◽  
Local Density ◽  
Tight Binding ◽  
Amorphous Metal ◽  
Range Order ◽  
Tight Binding Approximation ◽  
Electronic Parameters ◽  
Local Electronic Structure

The relationship between topological short-range order and a local electronic structure was analyzed in the computer model of an amorphous metal. The model, obtained by means of the original self-consistent cluster simulation procedure was studied with the use of Voronoi tesselation, the distribution of the atomic level stresses and the icosahedral order parameters. It was found that a marked correlation exists within 2 atomic parameter groups, one of which corresponds to the local dilatation and the other to the spherical symmetry distortion. The local density of electronic d-states (DOS) and the distribution of the electronic parameters was analyzed. The local electronic structure, calculated within the tight-binding approximation, appears to depend on the local atomic order by two-fold means: the interatomic distances decrease leads to the increase of the local bandwidth, and the icosahedral configuration distortion reduces the DOS at the Fermi level. The study of the local configurations stability shows, that the most stable configurations are the slightly distorted icosahedra.

ELECTRONIC STRUCTURE OF SHORT CARBON NANOBELLS

2003 ◽  
Vol 17 (09) ◽  
pp. 375-382 ◽  
Author(s):  
G. L. ZHAO ◽  
D. BAGAYOKO ◽  
E. G. WANG
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Local Density ◽  
Emission Characteristics ◽  
Local Density Of States ◽  
Nitrogen Doped ◽  
Local Density Functional ◽  
Nitrogen Doped Carbon ◽  
Short Carbon ◽  
Open Edge

We performed local density functional calculations for the electronic structure of short carbon nanobells. The calculated local density of states of the nanobells revealed field emission characteristics that agree with experimental observations. We also performed total energy calculations to study the structural stability and a related possible growth mechanism of the nanobells. In the nitrogen-doped carbon nanobells, nitrogen atoms that are attracted to the open-edge sites of the carbon nanobells appear to stop the growth of the nanostructures.

A Tight-Binding Hamiltonian for the High-Temperature Superconductor YBa2Cu3O7

1988 ◽  
Vol 141 ◽  
Author(s):  
M.J. DeWeert ◽  
D.A. Papaconstantopoulos ◽  
W.E. Pickett
Keyword(s):  
Electronic Structure ◽  
High Temperature ◽  
Band Structure ◽  
Potential Application ◽  
Oxygen Vacancies ◽  
High Temperature Superconductor ◽  
Tight Binding ◽  
Coherent Potential Approximation ◽  
Potential Approximation

AbstractWe present a highly accurate tight-binding parametrization of the LAPW band structure of the high-temperature superconductor YBa2Cu3O7, discuss the methodology used in obtaining this fit, and its potential application to a Tight-Binding Coherent-Potential Approximation (TB-CPA) calculation of the effects of oxygen vacancies on the electronic structure.

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