Relation between oxygen stoichiometry and thermodynamic properties and the electronic structure of nonstoichiometric perovskite La0.6Sr0.4CoO3−δ

2016 ◽  
Vol 18 (42) ◽  
pp. 29543-29548 ◽  
Author(s):  
S. F. Bychkov ◽  
A. G. Sokolov ◽  
M. P. Popov ◽  
A. P. Nemudry
Keyword(s):  
Electronic Structure ◽  
Thermodynamic Properties ◽  
Fermi Level ◽  
Electronic States ◽  
Oxygen Activity ◽  
Oxygen Stoichiometry ◽  
Itinerant Electron ◽  
Electron Model ◽  
Density Of Electronic States

Within the framework of the itinerant electron model, the dependence of the oxide nonstoichiometry on the oxygen activity was related to the density of electronic states near the Fermi level.

scholarly journals Электронные состояния наносистем на основе сульфида кадмия в форме сфалерита

2019 ◽  
Vol 53 (10) ◽  
pp. 1419
Author(s):  
В.Г. Заводинский ◽  
А.П. Кузьменко
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Fermi Level ◽  
Cadmium Sulfide ◽  
Density Functional ◽  
Electronic States ◽  
Functional Theory ◽  
Density Of Electronic States ◽  
The Density Functional Theory ◽  
Semiconductor Properties

The electronic structure of nanosystems on the basis of cadmium sulfide in a blende phase (zb-CdS) is investigated using the method of the density functional theory and pseudo-potentials. It is shown that the used approach allows to describe electronic states of this material rather correctly. It is revealed that the surface (100) - zb-CdS is characterized by the metal-like density of electronic states while the surfaces (110) - zb-CdS has a forbidden band at the Fermi level, and nanofilms with this orientation can be used as material for semiconductor devices. Epitaxial layered nanosystems (110) - zb-CdS-Si also show semiconductor properties.

Electronic structure of NixTiSe2 (0.05 ≤ x ≤ 0.46) compounds with ordered and disordered Ni

2017 ◽  
Vol 19 (6) ◽  
pp. 4500-4506 ◽  
Author(s):  
A. S. Shkvarin ◽  
Yu. M. Yarmoshenko ◽  
A. I. Merentsov ◽  
Yu. M. Zhukov ◽  
A. A. Titov ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectroscopy ◽  
Theoretical Calculations ◽  
Electronic States ◽  
Intercalation Compounds ◽  
X Ray ◽  
Density Of Electronic States ◽  
X Ray Absorption

The electronic structure of NixTiSe2 intercalation compounds with disordered and ordered Ni atoms is studied using photoelectron, resonant photoelectron and X-ray absorption spectroscopy, theoretical calculations of the X-ray spectra and density of electronic states.

scholarly journals Электронная структура и оптические спектры соединений GdFeAl и GdFeSi

2021 ◽  
Vol 63 (6) ◽  
pp. 700
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин ◽  
А.Г. Кучин ◽  
С.П. Платонов
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Comparative Analysis ◽  
Optical Conductivity ◽  
Electronic States ◽  
Wavelength Interval ◽  
Correlation Effects ◽  
Calculated Density ◽  
Density Of Electronic States ◽  
Conductivity Spectra

Results of investigations of electronic structure and optical properties of GdFeAl and GdFeSi compounds are presented. Spin-plarized density of states and interband optical conductivity spectra were calculated in frame of DFT+U technique with a correction for strong correlation effects in 4f shell of Gd. Optical properties were measured by ellipsometric technique in wavelength interval of 0.22 – 16 μm. Nature of quantum light absorption is discussed on the base of comparative analysis of experimental and calculated spectra. It is shown that main features of frequency dependencies of the optical conductivity are interpret qualitatively by the calculated density of electronic states.

scholarly journals Investigation of Electronic Structure of Zr1-xVxNiSn Semiconductive Solid Solution

2019 ◽  
Vol 20 (2) ◽  
pp. 127-132
Author(s):  
Yu.V. Stadnyk ◽  
V.V. Romaka ◽  
V.A. Romaka ◽  
A.M. Нoryn ◽  
L.P. Romaka ◽  
...  
Keyword(s):  
Solid Solution ◽  
Electronic Structure ◽  
Electrical Properties ◽  
Band Gap ◽  
Electronic States ◽  
Structural Defects ◽  
Simultaneous Generation ◽  
Density Of Electronic States ◽  
Donor And Acceptor ◽  
Donor Acceptor

The peculiarities of electronic and crystal structures of Zr1-xVxNiSn (x = 0 - 0.10) semiconductive solid solution were investigated. To predict Fermi level εF behavior, band gap εg and electrokinetic characteristics of Zr1-xVxNiSn, the distribution of density of electronic states (DOS) was calculated. The mechanism of simultaneous generation of structural defects of donor and acceptor nature was determined based on the results of calculations of electronic structure and measurement of electrical properties of Zr1-xVxNiSn semiconductive solid solution. It was established that in the band gap of Zr1-xVxNiSn the energy states of the impurity donor εD2 and acceptor εA1 levels (donor-acceptor pairs) appear, which determine the mechanisms of conduction of semiconductor.

Atomic-Scale Imaging

2021 ◽  
pp. 187-234
Author(s):  
C. Julian Chen
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Fermi Level ◽  
Electronic States ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
First Principle ◽  
Spin Polarized ◽  
Quantitative Explanation

This chapter discusses the imaging mechanism of STM and AFM at the atomic scale. Experimental facts show that at atomic resolution, tip electronic states play a key role. Analytic theoretical treatments provide quantitative explanation of the effect of the tip electronic states. On transition-metal tips, first-principle studies unanimously show that d-type tip electronic states dominate the Fermi-level DOS. First-principle studies of the combined tip-sample systems show that for both STM and AFM, the p- and d-type tip electronic states are the keys to understanding the atomic-scale images. The case of spin-polarized STM and the chemical identification of surface atoms are also discussed in terms of tip electronic structure. The chapter concludes with discussions of experimental verifications of the reciprocity principle: at atomic resolution, the role of tip electronic states and the sample electronic states are interchangeable.

Electronic Structure of Disordered Binary Alloys: α-Brass

1972 ◽  
Vol 50 (22) ◽  
pp. 2856-2865 ◽  
Author(s):  
M. P. Das ◽  
S. K. Joshi
Keyword(s):  
Electronic Structure ◽  
Binary Alloys ◽  
Electronic States ◽  
Potential Approximation ◽  
Function Type ◽  
Density Of Electronic States ◽  
Photoemission Data ◽  
The Green Function ◽  
Type Potential ◽  
Disordered Alloy

We have given a brief review of the existing approaches towards the study of the electronic structure of disordered binary alloys and have discussed Soven's single-site coherent potential approximation. An angular momentum representation of the Green function with Slater's δ-function-type potential is used to calculate the spectral density of electronic states of the disordered alloy, α-brass. We have compared the results of our calculation with available optical and photoemission data.

The semiconductor-electrolyte interface

1996 ◽  
Author(s):  
Wolfgang Schmickler
Keyword(s):  
Electronic Structure ◽  
Fermi Level ◽  
Band Gap ◽  
Electric Current ◽  
Valence Band ◽  
Conduction Band ◽  
Electronic States ◽  
Electrochemical Reactions ◽  
Electrochemical Interface ◽  
Semiconductor Chips

Many naturally occurring substances, in particular the oxide films that form spontaneously on some metals, are semiconductors. Also, electrochemical reactions are used in the production of semiconductor chips, and recently semiconductors have been used in the construction of electrochemical photocells. So there are good technological reasons to study the interface between a semiconductor and an electrolyte. Our main interest, however, lies in more fundamental questions: How does the electronic structure of the electrode influence the properties of the electrochemical interface, and how does it affect electrochemical reactions? What new processes can occur at semiconductors that are not known from metals? We begin by recapitulating a few facts about semiconductors. Electronic states in a perfect semiconductor are delocalized just as in metals, and there are bands of allowed electronic energies. According to a well-known theorem, bands that are either completely filled or completely empty do not contribute to the conductivity. In semiconductors the current-carrying bands do not overlap as they do in metals; they are separated by the band gap, and the Fermi level lies right in this gap. The band below the Fermi level, which at T = 0 is completely filled, is known as the valence band; the band above, which is empty at T = 0, is the conduction band. In a pure or intrinsic semiconductor, the Fermi level is close to the center of the band gap. At room temperature a few electrons are excited from the valence into the conduction band, leaving behind electron vacancies or holes (denoted by h+). The electric current is carried by electrons in the conduction band and holes in the valence band. The concentrations nc of the conduction electrons and pv of the holes are determined from Fermi statistics.

scholarly journals Электронная структура и оптические свойства соединения FeAl-=SUB=-2-=/SUB=-

2020 ◽  
Vol 62 (1) ◽  
pp. 85
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Intermetallic Compound ◽  
Optical Conductivity ◽  
Magnetic Moments ◽  
Electronic States ◽  
Spectral Interval ◽  
Calculated Density ◽  
Density Of Electronic States ◽  
Spin Polarized

Electronic structure and optical properties of the FeAl2 intermetallic compound are investigated. Spin-polarized calculations of the electronic structure were carried out, magnetic moments of the atoms were determined. Optical properties of the compound were measured by ellipsometric technique in spectral interval 0.22 – 15 μm. It is shown that the experimental optical conductivity is satisfactory interpreted on the base of the calculated density of electronic states.

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