SURFACE EFFECTS ON THE STATISTICS OF THE LOCAL DENSITY OF STATES IN METALLIC NANOPARTICLES: MANIFESTATION ON THE NMR SPECTRA

In metallic nanoparticles, shifts in the ionization energy of surface atoms with respect to bulk atoms can lead to surface bands. Within a simple Tight Binding model we find that the projection of the electronic density of states on these sites presents two overlapping structures. One of them is characterized by the level spacing coming from bulk states and the other arises from the surface states. In very small particles, this effect contributes to an over-broadening of the NMR absorption spectra, determined by the Knight shift distribution of magnetic nuclei. We compare our calculated Knight shifts with experiments on aluminum nanoparticles, and show that the deviation of the scaling law as a function of temperature and particle size can be explained in terms of surface states.

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Localization of electrons and influence of surface states on the density of states in a tight-binding model on the Penrose tiling

Materials Science and Engineering A ◽

10.1016/s0921-5093(00)01146-1 ◽

2000 ◽

Vol 294-296 ◽

pp. 886-889 ◽

Cited By ~ 7

Author(s):

E.S Zijlstra ◽

T Janssen

Keyword(s):

Density Of States ◽

Tight Binding ◽

Surface States ◽

Penrose Tiling ◽

Tight Binding Model ◽

Binding Model ◽

Localization Of Electrons

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Effect of the Local Disorder in a-Si on the Electronic Density of States at the Band Edges.

MRS Proceedings ◽

10.1557/proc-219-581 ◽

1991 ◽

Vol 219 ◽

Cited By ~ 2

Author(s):

B. N. Davidson ◽

G. Lucovsky ◽

J. Bernholc

Keyword(s):

Density Of States ◽

Nearest Neighbor ◽

Bond Angle ◽

Local Density ◽

Tight Binding ◽

Bethe Lattice ◽

Neighbor Interaction ◽

Lattice Method ◽

Electronic Density ◽

Interaction Terms

ABSTRACTWe have systematically investigated the formation of electronic states in the region of the conduction and valence band edges of a Si as functions of variations in the bond angle distributions. Local Density of States (LDOS) for Si atoms in disordered environments have been calculated using the cluster Bethe lattice method with a tight-binding Hamiltonian containing both first and second nearest neighbor interaction terms. LDOS for atoms with bond angle dis ortions in the nearest neighbor and second neighbor shells are compared and contrasted, both showing an influence on the LDOS near the gap. We also consider the role of the second neighbor term in the Hamiltonian by comparing the DOS for a distoned infinite Bethe lattice using Hamiltonians with and without the second neighbor interactions. It is found that in this case the second neighbor interaction terms cause greater conduction band tailing than using the nearest neighbor interaction terms alone.

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Electronic properties of disordered zigzag carbon nanotubes

International Journal of Modern Physics B ◽

10.1142/s0217979215500204 ◽

2015 ◽

Vol 29 (05) ◽

pp. 1550020 ◽

Cited By ~ 1

Author(s):

Hamed Rezania

Keyword(s):

Density Of States ◽

Nitrogen Doping ◽

Energy Gap ◽

Tight Binding ◽

Binding Model ◽

Electronic Density ◽

Model Hamiltonian ◽

Donor And Acceptor ◽

Clean System ◽

Gap Width

We study the density of states of zigzag carbon nanotube (CNT) doped with both Boron and nitrogen atoms as donor and acceptor impurities, respectively. The effect of scattering of the electrons on the electronic spectrum of the system can be obtained via adding random on-site energy term to the tight binding model Hamiltonian which describes the clean system. Green's function approach has been implemented to find the behavior of electronic density. Due to Boron (Nitrogen) doping, Fermi surface tends to the valence (conduction) band of semiconductor CNT so that the energy gap width reduces. Furthermore the density of states of disordered metallic zigzag CNTs includes a peak near the Fermi energy.

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ELECTRONIC STATES AND LOCAL DENSITY OF STATES NEAR GRAPHENE CORNER EDGE

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512006058 ◽

2012 ◽

Vol 11 ◽

pp. 151-156 ◽

Cited By ~ 1

Author(s):

YUJI SHIMOMURA ◽

YOSITAKE TAKANE ◽

KATSUNORI WAKABAYASHI

Keyword(s):

Density Of States ◽

Nearest Neighbor ◽

Local Density ◽

Tight Binding ◽

Localized States ◽

Destructive Interference ◽

Edge States ◽

Local Density Of States ◽

Binding Model ◽

Recursion Method

We study that stability of edge localized states in semi-infinite graphene with a corner edge of the angles 60°, 90°, 120° and 150°. We adopt a nearest-neighbor tight-binding model to calculate the local density of states (LDOS) near each corner edge using Haydock's recursion method. The results of the LDOS indicate that the edge localized states stably exist near the 60°, 90°, and 150° corner, but locally disappear near the 120° corner. By constructing wave functions for a graphene ribbon with three 120° corners, we show that the local disappearance of the LDOS is caused by destructive interference of edge states and evanescent waves.

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

Modern Physics Letters B ◽

10.1142/s0217984904007463 ◽

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.

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An Ab-Initio Multicenter Tight-Binding Model for Molecular Dynamics Simulations

MRS Proceedings ◽

10.1557/proc-141-25 ◽

1988 ◽

Vol 141 ◽

Author(s):

Otto F. Sankey ◽

David J. Niklewski

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Local Density ◽

Tight Binding ◽

Real Space ◽

Hamiltonian Matrix ◽

Binding Model ◽

Annealing Study ◽

Total Energies ◽

Dynamics Simulations

AbstractA new, approximate method has been developed for computing total energies and forces for a variety of applications including molecular dynamics simulations of covalent materials. The method is tight-binding-like and is based on the local density approximation within the pseudopotential scheme. Slightly excited pseudo-atomic-orbitals are used, and the tight-binding Hamiltonian matrix is obtained in real space. The method is used to find the total energies for five crystalline phases of Si and the Si 2 molecule. Excellent agreement is found with experiment. A molecular dynamics simulated annealing study has been performed on the Si 3 molecule to determine the ground state configuration.

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

Canadian Journal of Physics ◽

10.1139/cjp-2019-0218 ◽

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.

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