scholarly journals Electronic Energy in Itinerant-Electron Metamagnetism

1994 ◽  
Vol 17 (3) ◽  
pp. 177-178 ◽  
Author(s):  
M. A. Grado Caffaro ◽  
M. Grado Caffaro
Keyword(s):  
Density Of States ◽  
Electronic Energy ◽  
Itinerant Electron

Electronic energy in the context of itinerant-electron metamagnetism is considered in a new way. In particular, the minimal value of this energy is calculated within the Stoner model. To get this end, an elliptic density of states is used.

scholarly journals A Brief Study on Energy in Itinerant-Electron Metamagnetic Materials at Very Low Temperature

1997 ◽  
Vol 20 (2) ◽  
pp. 91-94
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro
Keyword(s):  
Low Temperature ◽  
Total Energy ◽  
Density Of States ◽  
Electronic Energy ◽  
Itinerant Electron ◽  
Very Low Temperature

Electronic energy is calculated explicitly for itinerant-electron metamagnetic materials at very low temperature. This calculation involves bandwidth and consequently volume, and it has been performed by means of an elliptic density of states. Moreover, total energy is considered.

Parameter free calculation of the subgap density of states in poly(3-hexylthiophene)

2014 ◽  
Vol 174 ◽  
pp. 255-266 ◽  
Author(s):  
Jarvist M. Frost ◽  
James Kirkpatrick ◽  
Thomas Kirchartz ◽  
Jenny Nelson
Keyword(s):  
Density Of States ◽  
Energy Levels ◽  
Tight Binding ◽  
Electronic Energy ◽  
Film Structure ◽  
Dynamics Simulation ◽  
Characteristic Energy ◽  
Torsional Potential ◽  
Experimental Values ◽  
Electronic Energy Levels

We investigate the influence of intra-chain and inter-chain interactions on the sub-gap density of states in a conjugated polymer using a combination of atomistic molecular dynamics simulation of polymer film structure and tight-binding calculation of electronic energy levels. For disordered assemblies of poly-3-hexylthiophene we find that the tail of the density of hole states is approximately exponential with a characteristic energy of 37 meV, which is similar to experimental values. This tail of states arises mainly from variations in the electronic coupling between neighbouring monomers, and is only slightly influenced by interchain coupling. Thus, knowledge of the disorder in torsion between neighbouring monomers is sufficient to estimate the density of states for the polymer. However, the intrachain torsional disorder is determined largely by the packing of the chains rather than the torsional potential alone. We propose the combination of methods as a tool to design higher mobility conjugated polymers.

HYDROGEN BONDING IN DIAMOND: A COMPUTATIONAL STUDY

2006 ◽  
Vol 17 (07) ◽  
pp. 959-966 ◽  
Author(s):  
O. OFER ◽  
JOAN ADLER ◽  
A. HOFFMAN
Keyword(s):  
Density Of States ◽  
Fermi Energy ◽  
Computational Study ◽  
Tight Binding ◽  
Local Deformation ◽  
Electronic Energy ◽  
Hydrogen Atoms ◽  
High Hydrogen ◽  
New Energy ◽  
Energy States

We present tight binding molecular dynamics simulations of the diffusion and bonding of hydrogen in bulk diamond. The motion of hydrogen atoms and the resultant structural and electronic energy level changes are investigated. The hydrogen atoms were found to have a tendency to migrate to the surface layer of diamond, resulting in a local deformation of the lattice, creating new energy states above and below the Fermi energy in the bandgap of the diamond density of states. In the diamond bulk, at high hydrogen concentrations, vacancies created by a hydrogen atom are quickly filled with other hydrogen atoms causing a deformation of the diamond lattice, inducing H 2 formation. This creates new energy states above the Fermi energy and reduces the secondary bandgap of the diamond density of states.

scholarly journals Some Considerations on Electronic Energy of Itinerant-electron Metamagnetic Materials with Volume-dependent Exchange Energy

2001 ◽  
Vol 24 (1) ◽  
pp. 63-67 ◽  
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro ◽  
S. L. Sapienza
Keyword(s):  
Electronic Energy ◽  
Exchange Energy ◽  
Itinerant Electron ◽  
Average Value

Electronic energy of itinerant-electron metamagnetic materials is examined by taking into consideration volume-dependent exchange energy between up and down spin electrons. In particular, the average value of the electronic energy is formulated in terms of the energy bandwidth which is closely related to volume; from the above average value, the average value of the exchange energy may be evaluated.

scholarly journals Exchange interaction in itinerant-electron metamagnetism

2018 ◽  
Vol 39 (1) ◽  
pp. 31-34
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro
Keyword(s):  
Magnetic Field ◽  
Matrix Element ◽  
Exchange Interaction ◽  
Hamiltonian Operator ◽  
Electronic Energy ◽  
Itinerant Electron ◽  
Multiplicative Constant ◽  
Absolute Value ◽  
The Matrix ◽  
The Difference

Abstract The exchange interaction in itinerant-electron metamagnetism is investigated theoretically. In fact, by considering spin-up and spin-down electrons in an itinerant-electron metamagnetic gas in the presence of an external magnetic field, we show that the difference between the Fermi energies of the spin-up and spin-down electrons equals, up to a multiplicative constant, the absolute value of the matrix element of the Hamiltonian operator relative to the interaction in question. Furthermore, the Stoner formula for the electronic energy of the gas is used to study the size of the exchange interaction.

Electronic energy transfer: density of states

1993 ◽  
Vol 97 (50) ◽  
pp. 13046-13051 ◽  
Author(s):  
Mita Chattoraj ◽  
Basil Paulson ◽  
Yan Shi ◽  
G. L. Closs ◽  
Donald H. Levy
Keyword(s):  
Energy Transfer ◽  
Density Of States ◽  
Electronic Energy ◽  
Electronic Energy Transfer

Mathematical–Physics Investigation on the Behaviour of a Metamagnetic System

2017 ◽  
Vol 72 (5) ◽  
pp. 463-467 ◽  
Author(s):  
M.A. Grado-Caffaro ◽  
M. Grado-Caffaro
Keyword(s):  
Magnetic Susceptibility ◽  
Energy Eigenvalue ◽  
Mathematical Physics ◽  
Electronic Energy ◽  
Absolute Temperature ◽  
Itinerant Electron ◽  
Eigenvalue Spectrum ◽  
Matrix Formulation ◽  
Band Energy ◽  
Key Aspects

AbstractIn order to exemplify, we consider a finite itinerant-electron metamagnetic gas at sufficiently low absolute temperature so that relevant new results are obtained. In fact, we study key aspects related to derive the electronic energy of the abovementioned metamagnetic gas in relation to the Fermi levels of the spin-up and spin-down electron bands and in relation to the exchange energy and magnetic susceptibility. Within an unprecedented mathematical–physics approach, the abovementioned electronic energy is reinterpreted by defining it as an averaged quantity from the corresponding nonrelativistic, time-independent, Schrödinger equation with two-band energy-eigenvalue spectrum. In parallel, a matrix formulation is presented.

scholarly journals Progressively Doping Graphene with S i: from Graphene to Silicene, a Numerical Study

2015 ◽  
Vol 7 (6) ◽  
pp. 1 ◽  
Author(s):  
Nathalie Olivi-Tran
Keyword(s):  
Density Of States ◽  
Mechanical Stability ◽  
Numerical Study ◽  
Graphene Nanosheets ◽  
Electronic Energy ◽  
Total Electronic Energy ◽  
Doped Graphene

For three different sizes of graphene nanosheets, we computed the Density of states when these nanosheets are progressively doped with an increasing percentage of S i atoms. The pure graphene nanosheets are semi conducting or not depending on their size. The pure silicene nanosheets are conducting with a conduction due to π (pi) electrons. <br />The S i doped graphene nanosheets are also semi conducting or not depending on their size: for small sizes, there are semi conducting and they become conducting for larger sizes and larger percentages of S idoping. We computed also the total electronic energy which is linked to the mechanical stability of all our nanosheets. This mechanical stability decreases regularly as a function of the S i percentage of doping , but for the pure silicene nanosheets, the mechanical stability decreases more abruptly.

scholarly journals Geometric and Electronic Properties of Monolayer HfX2 (X = S, Se, or Te): A First-Principles Calculation

2021 ◽  
Vol 7 ◽  
Author(s):  
Thi My Duyen Huynh ◽  
Duy Khanh Nguyen ◽  
Thi Dieu Hien Nguyen ◽  
Vo Khuong Dien ◽  
Hai Duong Pham ◽  
...  
Keyword(s):  
Density Of States ◽  
First Principles ◽  
Three Dimensional ◽  
Electronic Energy ◽  
First Principles Calculation ◽  
Edge States ◽  
Essential Properties ◽  
Theoretical Predictions ◽  
Physical Phenomena ◽  
Geometric And Electronic Properties

The essential properties of monolayer HfX2 (X = S, Se, or Te) are fully explored by first-principles calculations. The optimal lattice symmetries, sublattice buckling, electronic energy spectra, and density of states are systematically investigated. Monolayer HfS2, HfSe2, and HfTe2, respectively, belong to middle-gap semiconductor, narrow-gap one and semimetal, with various energy dispersions. Moreover, the van Hove singularities (vHs) mainly arise from the band-edge states, and their special structures in the density of states strongly depend on their two or three-dimensional structures and the critical points in the energy-wave-vector space. The above-mentioned theoretical predictions are attributed to the multi-orbital hybridizations of [dx2−y2, dxy, dyz, dzx, dz2]–[s, px, py, pz] in the Hf-X chemical bonds. The diversified physical phenomena clearly indicate a high potential for applications, as observed in MoS2-related emergent materials ions.

Electronic Properties of Au-Doped Narrow Armchair Graphene Nanoribbons: A First Principle Calculations

2014 ◽  
Vol 1015 ◽  
pp. 155-158
Author(s):  
Wei Hua Wang ◽  
Cui Lan Zhao ◽  
Xin Jun Ma
Keyword(s):  
Charge Density ◽  
Valence Band ◽  
Density Of States ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Local Density ◽  
Electronic States ◽  
Electronic Energy ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene

The centre Au-doped armchair graphene nanoribbons (AGNRs) are investigated using the local density approximation based on density function theory. The charge density, electronic energy band and project density of states of centre Au-doped AGNRs are calculated. Our results indicate the charge density is transferred between C and Au atoms and mainly located on the Au atoms. The centre Au-doped AGNRs are an indirect band gap semiconductor with an energy gap of 1.046 eV. The Fermi level is located on valence band so that the AGNRs of doping Au become into degenerate semiconductor. The project density of states is calculated to reveal localization and hybridization between C-2pand Au-6s, 5delectronic states. The localization and hybridization are much stronger in the valence band. The hybridization between C-2pand Au-6pelectronic states are strongly in the conduction band.

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