Interplay Between Local Environment Effect and Electronic Structure Properties in Close Packed Structures

1990 ◽  
Vol 206 ◽  
Author(s):  
P. E. A. Turchi
Keyword(s):  
Tight Binding ◽  
Local Environment ◽  
Environment Effect ◽  
Crystalline Structures ◽  
Tcp Phases ◽  
Densities Of States ◽  
Valence Electrons ◽  
Local Densities ◽  
The Common ◽  
Fifth Order

ABSTRACTWithin a tight binding framework, the interplay between local atomic arrangement, orbital directionality and phase stability properties is discussed for a series of tetrahedrally close packed (tcp) structures. The common features which characterize the local densities of states of tcp phases can be explained by a moment analysis up to fourth order terms. On the contrary, it is shown that structural energy differences between simple and tcp crystalline structures requires the knowledge of at least the fifth order moments, a fact which has been underestimated in the past. Finally, the relative stability of various representative geometries, including the ones of simple crystalline structures is examined as a function of the number of valence electrons.

Electronic Structure of Epitaxial SiO2/Si(100) Interfaces

1989 ◽  
Vol 159 ◽  
Author(s):  
T. Motooka
Keyword(s):  
Tight Binding ◽  
Interface States ◽  
Photoelectron Spectra ◽  
Band Spectrum ◽  
Binding Model ◽  
Initial Oxidation ◽  
Recursion Method ◽  
Densities Of States ◽  
Local Densities ◽  
Gap States

ABSTRACTThe local densities of states (LDOS) of epitaxial SiO, layers on Si(100) surfaces have been calculated using the recursion method combined with the Harrison's universal tight-binding model. The interface states associated with strained epitaxial layers of β-cristobalite (√2×√2)R45° and tridymite (1010)<0001> || Si(100)<011> were examined. In the β-cristobalite layer, gap states due to the surface Si dangling bonds appeared while they were eliminated by H termination. In the tridymite layer, the interface states primarily composed of the surface Si back bonds appeared near the Si conduction band minimum. Comparing the calculated DOS with photoelectron spectra for initial oxidation processes of clean Si(100), it was found that the valence band spectrum from the initial oxide formed at ∼300°C resembled that of the β-cristobalite layer.

CALCULATION FOR A Cu(001) SURFACE WITH AN IMPURITY ATOM

1999 ◽  
Vol 13 (04) ◽  
pp. 389-396
Author(s):  
CHIH-KAI YANG
Keyword(s):  
Electronic Structure ◽  
Impurity Atom ◽  
Magnetic Moments ◽  
Tight Binding ◽  
Real Space ◽  
Structure Calculation ◽  
Spin Polarized ◽  
Densities Of States ◽  
Self Consistent ◽  
Local Densities

I use a self-consistent electronic structure calculation to study the system of Cu(001) that has an impurity atom replacing one of the surface Cu atoms. The calculation makes use of the tight-binding linear muffin-tin orbitals (TB-LMTO) and is carried out in real space. I am able to derive the spin-polarized local densities of states for the impurity Cr and Fe respectively, which have peaks below the Fermi level. Charge transfers between the impurities and their neighbors also result in different distributions of magnetic moments for the two impurity systems, with the Cr having approximately 0.5μ B and the Fe atom having a negligible magnetic moment.

Robust and controllable electronic local transports in armchair silicene nanoribbons under a perpendicular electric field

2017 ◽  
Vol 31 (21) ◽  
pp. 1750146 ◽  
Author(s):  
Xiongwen Chen ◽  
Zhengang Shi ◽  
Baoju Chen ◽  
Kehui Song
Keyword(s):  
Electric Field ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Structural Defects ◽  
Tight Binding Approximation ◽  
Current Switch ◽  
Densities Of States ◽  
Silicene Nanoribbons ◽  
Local Densities ◽  
Transport Channels

We study the electronic local distribution and transports in pristine armchair-edge silicene nanoribbons (ASiNRs) based on the tight-binding approximation. By calculating the local densities of states at different sites and the bond current between two adjacent sites, we show that comparing to the pristine armchair-edge graphene nanoribbons, a similar “[Formula: see text]” rule and multiple low-electron transport channels exist in the pristine [Formula: see text]-ASiNRs. However, differently, they are controllable to appear and disappear by applying an electric field perpendicular to the ribbon plane. Therefore, one can manipulate the semiconducting channels and realize the current switch “on/off,” unchanging their structures. Moreover, the results are robust against the edge-passivation and a few structural defects, which ensures their stability for the practical application in the silicene-based device.

Nature Versus the Common Law

2021 ◽  
Author(s):  
David B. Schorr
Keyword(s):  
Common Law ◽  
Local Environment ◽  
Water Law ◽  
Public Ownership ◽  
Normative Force ◽  
The Common ◽  
English Law

This article recovers a debate, played out over the course of a century, in courts across the « common law world », over whether nature had normative force in water law. It explores areas of water law, such as the extent of public ownership in rivers and the effects of shifting watercourses on ownership, in which some courts, not without controversy, departed from the established rules of English law in order to make rules more appropriate, as they saw it, to the local environment.

Commentary on local densities of states, surface bonds and rate processes

1986 ◽  
Vol 318 (1541) ◽  
pp. 135-139 ◽  
Keyword(s):  
Electron Spectroscopy ◽  
Main Part ◽  
Catalytic Reactions ◽  
Solid Surfaces ◽  
Densities Of States ◽  
Rate Processes ◽  
Local Densities ◽  
Structure And Bonding ◽  
The Many

Although the main part of the title of this meeting is ‘ Studies of the surfaces of solids by electron spectroscopy’, the papers presented also cover some of the wider aspects of these studies, and I wish to pursue some of these here. I remark first that most of the systems studied by surface-sensitive spectroscopies are not technologically important, or even interesting in their own right. What makes them important and interesting is that the solids studied are, or are related to, catalysts, and the adsorbates studied are reactants, products or intermediates in important catalytic reactions. Consequently I ask the question: what is the relevance to catalysis of studies of structure, and bonding at solid surfaces? From among the many answers that might be given, I select two.

The influence of hydrogen saturation on the local densities of states in small Si, Ge and GaAs clusters

1981 ◽  
Vol 106 (1-3) ◽  
pp. A188
Author(s):  
G. de Meyer ◽  
R. Hoogewijs ◽  
W. Lambrecht ◽  
J. Vennik ◽  
G. Dalmai
Keyword(s):  
Hydrogen Saturation ◽  
Densities Of States ◽  
Local Densities
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