scholarly journals The Electrical Conductivity in Superlattices of Spherical Quantum Dots

2016 ◽  
Vol 17 (3) ◽  
pp. 320-328
Author(s):  
V.I. Boichuk ◽  
R.I. Pazyuk ◽  
I.V. Bilynskyi
Keyword(s):  
Electrical Conductivity ◽  
Quantum Dots ◽  
Electrical Properties ◽  
Fermi Level ◽  
Temperature Dependence ◽  
Group Velocity ◽  
Aluminum Concentration ◽  
The Matrix

The electrical properties of semiconductor systems of spherical GaAs / AlxGa1-xAs quantum dots of various dimensions, depending on the energy of the Fermi level and temperature, and the concentration of aluminum in the matrix, are investigated. Dependences of group velocity of electrons on the index of minisons were obtained. Reducing the CT radius, as well as increasing the aluminum concentration in the matrix, results in an increase in group velocity. The change in the sign of the group velocity of individual minisons is caused by the behavior of the isoenergetic surfaces of these minisons. The electrical conductivity is calculated, containing the contributions of the s- and three p-minisons for given parameters of the system, the maximum of which is near the center of the minisone. The increase in electrical conductivity is observed with a decrease in the CT radius and the aluminum concentration, as well as with the decrease of the GaAs / AlxGa1-xAs superlattice dimension. The temperature dependence of electrical conductivity for various parameters of such systems is also investigated.

The Influence of Annealing in Saturated Water Vapor on LiNbO3 Crystals Optical and Electrical Properties

2015 ◽  
Vol 230 ◽  
pp. 233-237 ◽  
Author(s):  
Aleksandr V. Yatsenko ◽  
A.S. Pritulenko ◽  
S.V. Yevdokimov ◽  
Dmytro Yu. Sugak ◽  
I.I. Syvorotka ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Water Vapor ◽  
Electrical Properties ◽  
Temperature Dependence ◽  
Optical Spectra ◽  
Optical And Electrical Properties ◽  
Saturated Water Vapor ◽  
Hydrogen Annealing ◽  
Saturated Water

The temperature dependence of the dark electrical conductivity of the LiNbO3(LN) crystals annealed in saturated H2O and D2O vapor in the range 293...400 K is investigated. It is found that the activation energy of the electrical conductivity is equal to (0.71 ± 0.02) eV and is close this value of LN samples, reduced in hydrogen. Annealing in ampoules with H2O vapor also lead to LN optical spectra changes such annealing in H2. The nature of this phenomenon is discussed.

Effects of Functionalization MWCNTs on the Mechanical and Electrical Properties of nylon-6 Composites

2013 ◽  
Vol 750-752 ◽  
pp. 127-131 ◽  
Author(s):  
Xiang Dong Zhu ◽  
Qing Jie Jiao ◽  
Chong Guang Zang ◽  
Xian Peng Cao
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Volume Ratio ◽  
Nylon 6 ◽  
Coupling Process ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotube ◽  
The Matrix ◽  
The Impact ◽  
Coupling Treatment

Chemically coupling functionalization multi-walled carbon nanotube (MWCNTs)/nylon-6 (PA6) composites were prepared. The nanotubes were first treated by a volume ratio of 3:1 mixture of concentrated H2SO4/HNO3, and then the γ-aminopropyl-triethoxysilane (KH-550) was carried onto the surface of MWCNTs. Effect of MWCNTs coupling treatment on the mechanical and electrical properties of the MWCNTs/PA6 composites were investigated. The impact strength, tensile strength and modulus of p-MWCNTs (coupling process)/PA6 composites increase by 115.9%, 27.2% and 167.7%, respectively, compared with those of the pure nylon-6 resin. A significant increase of the electrical conductivity of the p-MWCNTs/PA6 composites with respect to the original-MWCNTs and a-MWCNTs/PA6 composites due to the increased compatibility with the matrix due to the formation of an inter face with stronger interconnections.

scholarly journals Polaron Conduction and Optical Absorption of Amorphous Selenium Films

1974 ◽  
Vol 29 (5) ◽  
pp. 724-727 ◽  
Author(s):  
A. H. Abou El Ela
Keyword(s):  
Electrical Conductivity ◽  
Optical Absorption ◽  
Fermi Level ◽  
Temperature Dependence ◽  
Valence Band ◽  
Energy Gap ◽  
Amorphous Selenium ◽  
Experimental Results ◽  
Selenium Films ◽  
Absorption Measurements

Abstract The temperature dependence of electrical conductivity in amorphous selenium films is investigated. The experimental results show a polaronic conduction in the states near the Fermi level, in agreement with Mott’s model. Optical absorption measurements show the rate at which the valence band states fall off with energy into the energy gap.

scholarly journals Dependence of electrical properties of composition material from the structure of the matrix

2019 ◽  
pp. 23-29
Author(s):  
K.V. Kirilenko
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Energy Consumption ◽  
Composite Materials ◽  
Electrical Properties ◽  
Surface Temperature ◽  
Linear Chain ◽  
Localized States ◽  
Composition Material ◽  
The Matrix

In the context of rising energy costs and the need to use new energy sources, works aimed at raising the surface temperature of heat radiators with reduced energy consumption are of particular importance, and it is especially important if these processes are also accompanied by the effects of self-stabilization. Bulk materials do not possess these properties. However, materials whose dielectric matrix is also an active element can provide up to 10 - 30% of the thermal energy that will be released in the material, thereby increasing the surface temperature and without increasing energy consumption. Therefore, the study of composite materials with different matrices is relevant. This article the influence of the matrix material on the electrical properties of composite materials was examined. It was established that the microstructure morphology of resistive materials changes significantly depending on the matrix type. In composites based on matrix AlN, for the entire range of concentrations HfC, conducting cluster is formed with a metallic conductivity. For composite systems Al2O3-HfC and Si3N4-HfC thermoactivated hopping conduction between nearest neighboring states observed. Thus, for materials based on Si3N4 matrix at temperatures up to 300°C observed reduction of charge carriers concentration with increasing temperature. The approximation of the temperature dependence of the electrical conductivity was carried out on the basis of the following possible variants of the nature of the electrical conductivity, namely: jump conductivity (nonlocalized states, localized states in the tails of conduction and valence bands, localized states near the Fermi level), tunneling. It can be assumed that the formation of conductive clusters occurred under the influence of two factors: magnetic field and mechanical loading. When using the AlN matrix, the influence of the magnetic field on the structure formation is smallest. This conclusion can be drawn from the fact that the formed conductive clusters have the appearance of a linear chain structure.

Effect of Gamma Radiation on Structural, Optical and Electrical Properties of nanostructured CdHgTe Thin Films

2018 ◽  
Vol 1 (1) ◽  
pp. 26-31 ◽  
Author(s):  
B Babu ◽  
K Mohanraj ◽  
S Chandrasekar ◽  
N Senthil Kumar ◽  
B Mohanbabu
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Gamma Radiation ◽  
Glass Substrate ◽  
Gamma Ray ◽  
Optical And Electrical Properties ◽  
Deposition Technique ◽  
Polycrystalline Structure ◽  
Dc Electrical Conductivity

CdHgTe thin films were grown onto glass substrate via the Chemical bath deposition technique. XRD results indicate that a CdHgTe formed with a cubic polycrystalline structure. The crystallinity of CdHgTe thin films is gradually deteriorate with increasing the gamma irradiation. EDS spectrums confirms the presence of Cd, Hg and Te elements. DC electrical conductivity results depicted the conductivity of CdHgTe increase with increasing a gamma ray dosage

Effect of the structure of cellulose acetate membranes on their permeability, electrical conductivity and rejection

1990 ◽  
Vol 55 (12) ◽  
pp. 2933-2939 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Klaus Richau
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Water Flux ◽  
Cellulose Acetate Membrane ◽  
Structure Parameters ◽  
Dc Electrical Conductivity ◽  
Cellulose Acetate Membranes

Ultrafiltration cellulose acetate membrane can be transformed by annealing into reverse osmosis membranes (RO type). Annealing brings about changes in structural properties of the membranes, accompanied by changes in their permeability behaviour and electrical properties. Correlations between structure parameters and electrochemical properties are shown for the temperature range 20-90 °C. Relations have been derived which explain the role played by the dc electrical conductivity in the characterization of rejection ability of the membranes in the reverse osmosis, i.e. rRO = (1 + exp (A-B))-1, where exp A and exp B are statistically significant correlation functions of electrical conductivity and salt permeation, or of electrical conductivity and water flux through the membrane, respectively.

Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substitution Effect ◽  
Dimensionless Figure Of Merit ◽  
The Matrix ◽  
Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

Enhanced electrical conductivity of Au–LaNiO3 nanocomposite thin films by chemical solution deposition

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 76783-76787 ◽  
Author(s):  
H. L. Wang ◽  
X. K. Ning ◽  
Z. J. Wang
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Chemical Solution Deposition ◽  
Nanocomposite Films ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Nanocomposite Thin Films ◽  
One Step

Au–LaNiO3 (Au–LNO) nanocomposite films with 3.84 at% Au were firstly fabricated by one-step chemical solution deposition (CSD), and their electrical properties were investigated.

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