scholarly journals The Influence of External Factors on Quantum Magnetic Effects in Electronic Semiconductor Structures

2020 ◽  
Vol 9 (5) ◽  
pp. 1557-1563
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
External Factors ◽  
Landau Levels ◽  
Quantum Oscillation ◽  
Narrow Gap ◽  
Integral Expression ◽  
Semiconductor Structures ◽  
Longitudinal Conductivity ◽  
Calculation Results

A theory is constructed of the temperature dependence of quantum oscillation phenomena in narrow-gap electronic semiconductors, taking into account the thermal smearing of Landau levels. Oscillations of longitudinal electrical conductivity in narrow-gap electronic semiconductors at various temperatures are studied. An integral expression is obtained for the longitudinal conductivity in narrow-gap electronic semiconductors, taking into account the diffuse broadening of the Landau levels. A formula is obtained for the dependence of the oscillations of longitudinal electrical conductivity on the band gap of narrow-gap semiconductors. The calculation results are compared with experimental data.

Modeling on the temperature dependence of the magnetic susceptibility and electrical conductivity oscillations in narrow-gap semiconductors

2020 ◽  
Vol 34 (07) ◽  
pp. 2050052
Author(s):  
U. I. Erkaboev ◽  
G. Gulyamov ◽  
J. I. Mirzaev ◽  
R. G. Rakhimov
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Landau Levels ◽  
Experimental Results ◽  
Quantum Oscillation ◽  
Narrow Gap ◽  
Narrow Gap Semiconductors ◽  
Longitudinal Conductivity ◽  
Different Temperatures

Electrical conductivity oscillations, magnetic susceptibility oscillations and electronic heat capacity oscillations for narrow-gap electronic semiconductors are considered at different temperatures. A theory is constructed of the temperature dependence of quantum oscillation phenomena in narrow-gap electronic semiconductors, taking into account the thermal smearing of Landau levels. Oscillations of longitudinal electrical conductivity in narrow-gap electronic semiconductors at various temperatures are studied. An integral expression is obtained for the longitudinal conductivity in narrow-gap electronic semiconductors, taking into account the diffuse broadening of the Landau levels. A formula is obtained for the dependence of the oscillations of longitudinal electrical conductivity on the bandgap of narrow-gap semiconductors. The theory is compared with the experimental results of [Formula: see text]. A theory is constructed of the temperature dependence of the magnetic susceptibility oscillations for narrow-gap electronic semiconductors. Using these oscillations of magnetic susceptibility, the cyclotron effective masses of electrons are determined. The calculation results are compared with experimental data. The proposed model explains the experimental results in [Formula: see text] at different temperatures.

scholarly journals Influence of Pressure on the Temperature Dependence of Quantum Oscillation Phenomena in Semiconductors

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
G. Gulyamov ◽  
U. I. Erkaboev ◽  
A. G. Gulyamov
Keyword(s):  
Experimental Data ◽  
Hydrostatic Pressure ◽  
Temperature Dependence ◽  
Band Gap ◽  
Landau Levels ◽  
Quantum Oscillation ◽  
Quantum Oscillations ◽  
Effect Of Pressure ◽  
Calculation Results

The influence of pressure on the oscillations of Shubnikov-de Haas (ShdH) and de Haas-van Alphen (dHvA) in semiconductors is studied. Working formula for the calculation of the influence of hydrostatic pressure on the Landau levels of electrons is obtained. The temperature dependence of quantum oscillations for different pressures is determined. The calculation results are compared with experimental data. It is shown that the effect of pressure on the band gap is manifested to oscillations and ShdH and dHvA effects in semiconductors.

Defect Chemistry and Basic Properties of Non-Stoichiometric PuO2

2017 ◽  
Vol 375 ◽  
pp. 57-70 ◽  
Author(s):  
Masato Kato ◽  
Hiroki Nakamura ◽  
Masashi Watanabe ◽  
Taku Matsumoto ◽  
Masahiko Machida
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Thermal Property ◽  
Ab Initio ◽  
Ab Initio Calculation ◽  
Oxygen Potential ◽  
Mechanistic Models ◽  
Basic Properties ◽  
Calculation Results ◽  
Equilibrium Defects

The basic properties of PuO2−x were reviewed, and the equilibrium defects in PuO2−x were evaluated from the experimental data of the oxygen potential and electrical conductivity as well as the Ab-initio calculation results. Consistency among various properties was confirmed, and the mechanistic models for thermal property representations were derived.

MATHEMATICAL MODELING OF TEMPERATURE EFFECT ON THE FAN CHART OF MAGNETOABSORPTION SPECTRUM IN SEMICONDUCTORS

2019 ◽  
pp. 104-115
Author(s):  
G. Gulyamov ◽  
U. I. Erkaboev ◽  
A. G. Gulyamov
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Field ◽  
Temperature Dependence ◽  
Density Of States ◽  
Landau Levels ◽  
Joint Density ◽  
Narrow Gap ◽  
Narrow Gap Semiconductors ◽  
Dispersion Law ◽  
The Magnetic Field

The article considers the oscillations of interband magneto-optical absorption in semiconductors with the Kane dispersion law. We have compared the changes in oscillations of the joint density of states with respect to the photon energy for different Landau levels in parabolic and non-parabolic zones. An analytical expression is obtained for the oscillation of the combined density of states in narrow-gap semiconductors. We have calculated the dependence of the maximum photon energy on the magnetic field at different temperatures. A theoretical study of the band structure showed that the magnetoabsorption oscillations decrease with an increase in temperature, and the photon energies nonlinearly depend on a strong magnetic field. The article proposes a simple method for calculating the oscillation of joint density of states in a quantizing magnetic field with the non-quadratic dispersion law. The temperature dependence of the oscillations joint density of states in semiconductors with non-parabolic dispersion law is obtained. Moreover, the article studies the temperature dependence of the band gap in a strong magnetic field with the non-quadratic dispersion law. The method is applied to the research of the magnetic absorption in narrow-gap semiconductors with nonparabolic dispersion law. It is shown that as the temperature increases, Landau levels are washed away due to thermal broadening and density of states turns into a density of states without a magnetic field. Using the mathematical model, the temperature dependence of the density distribution of energy states in strong magnetic fields is considered. It is shown that the continuous spectrum of the density of states, measured at the temperature of liquid nitrogen, at low temperatures turns into discrete Landau levels. Mathematical modeling of processes using experimental values of the continuous spectrum of the density of states makes it possible to calculate discrete Landau levels. We have created the three-dimensional fan chart of magneto optical oscillations of semiconductors with considering for the joint density of energy states. For a nonquadratic dispersion law, the maximum frequency of the absorbed light and the width of the forbidden band are shown to depend nonlinearly on the magnetic field. Modeling the temperature  dependence allowed us to determine the Landau levels in semiconductors in a wide temperature spectrum. Using the proposed model, the experimental results obtained for narrow-gap semiconductors are analyzed. The theoretical results are compared with experimental results.

Refined thermal calculation of the locomotive heat engine collector

2020 ◽  
pp. 56-58
Author(s):  
P.V. Gubarev ◽  
D.V. Glazunov ◽  
V.G. Ruban ◽  
A.S. Shapshal
Keyword(s):  
Experimental Data ◽  
Electric Motor ◽  
Heat Balance ◽  
Thermal Imaging ◽  
Heat Engine ◽  
Thermal Calculation ◽  
Calculation Results ◽  
Cooling Air ◽  
The Heat Balance ◽  
Traction Electric Motor

The thermal calculation of the locomotive traction engine collector is proposed. The equations of the heat balance of its elements are obtained taking into account the cooling air. The calculation results and experimental data of thermal imaging control are presented. Keywords: traction electric motor, collector, thermal calculation, thermal imaging control. [email protected]

Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites

2021 ◽  
pp. 108128652110214
Author(s):  
Xiaodong Xia ◽  
George J. Weng
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Nanocomposites ◽  
Electromagnetic Interference ◽  
Effective Medium Theory ◽  
Scale Model ◽  
Shielding Effectiveness ◽  
Emi Shielding

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.

Tests on Mechanical Properties and Anti-Penetration Performance of Steel-Fiber Reactive Powder Concrete

2013 ◽  
Vol 671-674 ◽  
pp. 1761-1765
Author(s):  
Yong Liu ◽  
Chun Ming Song ◽  
Song Lin Yue
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Reactive Powder Concrete ◽  
Calculation Results ◽  
Reactive Powder ◽  
Penetration Tests

In order to get mechanical properties ,some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. And a group of tests on RPC with 5% steel-fiber under penetration were also conducted to validate the performance to impact. The penetration tests are carried out by the semi-AP projectiles with the diameter of 57 mm and earth penetrators with the diameter of 80 mm, and velocities of the two kinds of projectiles are 300～600 m/s and 800～900 m/s, respectively. By contrast between the experimental data and the calculation results of C30 reinforced concrete by using experiential formula under penetration, it shows that the resistance of steel-fiber RPC to penetration is 3 times as that of general C30 reinforced concrete.

Studying the Effect of Fuel Elements Structural Materials Corrosion on their Operating Life

2021 ◽  
Vol 1038 ◽  
pp. 108-115
Author(s):  
Yuliana Hapon ◽  
Maksym Kustov ◽  
Volodumur Kalugin ◽  
Alexander Savchenko
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Fuel Element ◽  
State Level ◽  
External Factors ◽  
Economic Losses ◽  
Operating Life ◽  
Hydrodynamic Mode ◽  
Internal And External Factors ◽  
Fuel Elements

The paper deals with experimental data regarding the effect of internal and external factors on the corrosion decay of Zr1Nb alloy fuel elements. Based on the analysis results, losses of zirconium that transfers to oxide or coolant as per the fuel element wall weight and thickness as well as economic losses from their corrosion decay have been theoretically calculated. To avoid a state-level emergency occurrence, an increase in the fuel element wall thickness up to 660 μm is proposed, which can increase the operating life under the conditions of trouble-free coolant mass transfer hydrodynamic mode.

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