Electrical Conductivity of Molten Carbonate and Carbonate–Chloride Systems Coexisting with Aluminium Oxide Powder

2017 ◽  
Vol 73 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Elena V. Nikolaeva ◽  
Andrey L. Bovet ◽  
Irina D. Zakiryanova
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Specific Conductivity ◽  
Aluminium Oxide ◽  
Specific Electrical Conductivity ◽  
Impedance Method ◽  
Molten Carbonate ◽  
Composite Electrolytes ◽  
Two Phase ◽  
Oxide Concentration

AbstractThe electrical properties of composite electrolytes (suspensions) composed of α-Al2O3 powder and molten carbonate eutectic (Li2CO3–Na2CO3–K2CO3)eut or molten carbonate–chloride mixture 0.72(Li2CO3–Na2CO3–K2CO3)eut–0.28NaCl have been investigated by AC impedance method. This system shows a dependence of the electrical conductivity upon the temperature and the α-Al2O3 content. The specific electrical conductivity of the α-Al2O3/(Li2CO3–Na2CO3–K2CO3)eut system can be adequately described by the Maxwell equation for two-phase heterogeneous materials. The regression equation for the dependence of the specific conductivity of the α-Al2O3/(Li2CO3–Na2CO3–K2CO3)eut composite on the aluminium oxide concentration and temperature was obtained.

Electrical Conductivity of Magnesium Oxide/Molten Carbonate Eutectic Coexisting System

2019 ◽  
Vol 74 (9) ◽  
pp. 739-742
Author(s):  
Elena V. Nikolaeva ◽  
Andrey L. Bovet ◽  
Irina D. Zakiryanova
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Magnesium Oxide ◽  
Solid Phase ◽  
Specific Conductivity ◽  
Maxwell Model ◽  
Impedance Method ◽  
Molten Carbonate ◽  
Carbonate Ions ◽  
Alkali Carbonate

AbstractThe electrical conductivity of molten ternary alkali carbonate eutectic, coexisting with MgO particles, has been investigated. The conductivity was measured by the AC impedance method. The apparent activation energy ΔEa increased with the MgO content. This fact can be attributed to the effect of the solid phase. The specific conductivity of those systems could not be described using the Maxwell model over the solvation process of the carbonate ions on the particles of the magnesium oxide.

New Fabrication (PVA-CMC -PbO) Nanocomposites Structural and Electrical Properties

2021 ◽  
Vol 19 (4) ◽  
pp. 38-46
Author(s):  
Manar S. Toman ◽  
Sameer Hassan Al-nesrawy
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Electric Field ◽  
Lead Oxide ◽  
Optical Microscope ◽  
Structural And Electrical Properties ◽  
Oxide Concentration ◽  
Structural Aspects

This paper presents the work conducted on preparing (PbO PVA-PEG) nanocomposites through adding the different weight concentrations of lead oxide (0,1,3,5,7 wt%). The structural aspects such as optical microscope, FTIR and electrical features of nanocomposites (PVA-CMC/PbO) were examined. The resulting data shows that the dielectric constant decreased along with the decline of dielectric loss, whereas the frequency value rose while applying of an electric field. As for the electrical conductivity AC, the dielectric loss and dielectric constant of all samples rose along with the increase in lead oxide concentration.

scholarly journals Application of decomposition method for calculation of electrical conductivity of shungite based on the electron-microscopic cards of carbon distribution.

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
I.V. Antonets ◽  
◽  
E.A. Golubev ◽  
V.G. Shavrov ◽  
V.I. Shcheglov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Specific Resistance ◽  
Specific Conductivity ◽  
Specific Electrical Conductivity ◽  
Contact Method ◽  
Carbon Distribution ◽  
Conducting Phase ◽  
Flat Area ◽  
Black And White ◽  
Shungite Carbon

The outlook of using the shungite for covering large area which can protect something from electromagnetic radiation is described. As a main parameter which determines the efficiency of created screens is determined the specific electrical conductivity of shungite carbon. For the measuring of conductivity it is proposed to use the high-resolution raster electron microscopy which make be possible to obtain the card of carbon distribution in the scale of some nanometers. The method of binarization of this card is proposed. This binare card describes the spatial distribution of two phases – large-conducting and small-conducting. The large-conducting phase consist of graphene slides. The small-conducting phase consist of chaotic distributed atoms of carbon. On the basis of binare card it is constructed the flat-area block which is looked as net from square cells having two colours – black and white which correspond one by one to large and small-conducting phases. On the area of block it is selected tubes of current which consist of straight chains of black and white cells connected in succession. The whole resistance of block is determined by parallel connection of these tubes. It is proposed the procedure of constructing this symmetrical block along two coordinates. The scheme of this construction is proposed. The calculation of block resistivity along two coordinates is executed. On the basis of flat-area block it is constructed the space elementary block which has equal to each other resistance along three coordinates. For the determination of specific resistance of material as a whole it is carried out the procedure of decomposition which consist of presentation the unit volume of specimen as a set of elementary blocks. For the real specimens of shungite from two natural deposits it is made the calculation of specific resistance and specific conductivity of shungite carbon. It is established that the calculated data are coincide with data received by contact method in the accuracy of 30%. As a most advantage of proposed method it is established the possibility of conductivity measuring of carbon part of shungite in the scale of some units of nanometers.

scholarly journals Optical and Electrical Properties of Graphite Thin Films Prepared by Different Methods

2020 ◽  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electron Beam ◽  
Electrical Properties ◽  
Grain Boundaries ◽  
Barrier Height ◽  
Electron Beam Evaporation ◽  
Specific Electrical Conductivity ◽  
Simultaneous Increase ◽  
Optical And Electrical Properties

The paper reports on the structural, optical and electrical properties of graphite thin films prepared by two methods: the vacuum-free method "Pencil-on-semiconductor" and via the electron beam evaporation. Graphite thin films prepared by the non-vacuum method has annealed at a temperature of 920K.The transmission spectra of the investigated graphite films and the electrical properties of these thin films were measured at T = 300 K. The value of the height of barriers Eb at the grain boundaries and the temperature dependence of the electrical conductivity in the range ln(σ·T1/2) = f(103/T) were determined, It is established that the height of the barrier at the grain boundaries for the drawn graphite films is Eb = 0.03 eV, for annealed Eb = 0.01 eV and for the graphite films deposited by the electron beam evaporation Eb = 0.04 eV, ie for annealed film the barrier height is the smallest. It is shown that graphite films deposited by the electron beam evaporation reveals the highest transmittance (T550 ≈ 60%), and the transmission of drawn films is the lowest, annealing leads to its increase. The minimum values ​​of transmission at a wavelength λ = 250nm are due to the scattering of light at the defects that are formed at the grain boundaries. Annealed graphite films have been found to possess the best structural perfection because they have the lowest resistivity compared to non-annealed films and electron-beam films and have the lowest barrier height. Simultaneous increase of transmission in the whole spectral range, increase of specific electrical conductivity and decrease of potential barrier at grain boundaries of the annealed drawn graphite film clearly indicate ordering of drawn graphite flakes transferred onto anew substrate, which led to the reduction of light scattering and the improvement of charge transport due to the larger area of ​​overlap between graphite flakes.

scholarly journals Application of independent-channel method for investigation of electrical conductivity of graphene-containing shungite.

2021 ◽  
Author(s):  
I.V. Antonets ◽  
◽  
E.A. Golubev ◽  
V.G. Shavrob ◽  
V.I. Shcheglov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Spatial Distribution ◽  
Current Flow ◽  
Specific Conductivity ◽  
Specific Electrical Conductivity ◽  
Parallel Connection ◽  
Raster Electron Microscopy ◽  
Current Flows

The independent channel method which is intended for the calculation of specific electrical conductivity of graphene-contained shungite is proposed and realized on practice. It is noted that the most important of shungite application is the creation of screen hawing large area which are able to block electromagnetic radiation in wide frequency range. The most important factor which determines the blocking properties of shungite is the specific electrical conductivity of its carbon part which is determined by the spatial distribution of carbon atoms. As a main method of carbon structure investigation is mentioned the high-resolution raster electron microscopy which allows from the surface of specimen to receive the card of distribution of graphene slides and graphene packets. The spatial factor which determines the shungite conductivity is large anisotropy of single graphene slide which reaches three orders and more in the cases along and across the slide. The proposed method independent channels takes into consideration the arbitrary orientation of graphene packets relatively to direction of current flow. As a basis of method is employing the card of carbon spatial distribution which is received by raster electron microscopy method. The card is divided by parallel channels which transverse dimension is near or slightly exceeds the typical dimension of graphene packet. The channels are divided to square blocks which sides are equal to width of channel. The whole resistance of channel is formed by the successive connection of individual resistances of blocks. The resistance of whole card is determined by parallel connection of channels or averaging of resistance of all channels and following filling the whole area of card. The first step of analysis is the determination of advantage orientation of slides inside of every blocks. On the basis of determined orientation the block is filled by periodic structure which period is equal to the width of graphene slide and neighbouring interval. As a parameter which determines the orientation is used the angle between advantage orientation of graphene slides and axis of current flow between contacts. Owing to symmetry of task in comparison of current direction the limited meanings of corner is 0 and 90 degree. It is established two principal different cases of orientation: first – when determining angle is less than 45 degree and second when this angle is more than 45 degree. In the first case the current flows along the stripe with large conductivity. In the second case the current flows across these stripes so as through the stripes with low conductivity. It is found the smooth dependence of block resistivity from the angle of strip orientation. For the characteristic of area which is filled graphene slides it is proposed the coefficient of filling which is determined by binary discretization method. On the basis of analysis of slides orientation and filling coefficients are calculated the resistance of individual blocks. The resistances of all channels of investigated card are proposed. By using two methods – parallel connection and averaging over all channels it is calculated the specific electrical resistance and specific electrical conductivity of material as a whole. It is found that the received values of specific conductivity exceed the determined in experiment value in several (to 10) times. For the coordination of calculated value with experimental value it is made the variation of specific resistances of graphene slides and intervals between its. It id found that the calculation by method of parallel connection of channels ensures several better coordination than method of averaging. It is shown that the resistance is improved in the first turn by the increasing the resistance of interval between slides. In the quality of possible reason of decisive role of interval it is proposed the observed in experiment sharp non-homogeneity of relative arrangement of graphene slides. It is discussed the possible courses of further development of work. As a most important task it is proposed the more circumstantial determination of statistical character of received results.

Analytical description of sodium halogenides melts specific electric conductivity and its calculation for sodium astatide melt

2019 ◽  
Vol 60 (12) ◽  
pp. 125-132
Author(s):  
Ivan K. Garkushin ◽  
◽  
Olga V. Lavrenteva ◽  
Karina R. Gilmanova ◽  
Yana A. Andreeva ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Comparative Analysis ◽  
Ionic Radius ◽  
Specific Conductivity ◽  
Analytical Description ◽  
Specific Electrical Conductivity ◽  
Specific Electric Conductivity ◽  
Straight Line ◽  
Direct Equation ◽  
The Individual

The paper presents analytical and graphical dependences of the individual haloganides melts specific electrical conductivity æ of the sodium NaHal series (Hal – F, Cl, Br, I) on the halogen order number Z, ionic radius r of haloganide-ion Hal–, halogen ionic potential 1/r, reduced ionic radius r/Z, difference of electronegativity (∆χ = χ(Hal) – χ(Na)): æ = f(Z); æ = f(r); æ = f(1/r); æ = f(r/Z); æ = f(∆χ) for the temperature higher melting temperatures on 5, 10, 50, 75, 100, 150 и 200°. M.Kh. Karapetyans сomparative methods were applied for the description. The minimum standard deviation and maximum correlation coefficient corresponds to the equation æ–1 = a + bexp1/r, according to which the numerical values of æ(NaAt) are calculated for real temperatures. The temperature dependence æ of the NaAt melt is described by the equation æ = 0.0508+0.0023Т. A comparative analysis of the relationship between the specific electrical conductivity of NaHal melts at a temperature of Tm + n (n = 10 ... 200° higher the melting temperature) and æ at (Tm + 5°). A comparative analysis is represented by straightforward dependencies. It was shown that the specific electrical conductivity of the NaAt melt is related to the electrical conductivity of LiAt by the direct equation æ(NaAt) = 0.035+0.607æ(LiAt). The straight line equationalso relates æ of the NaHal melt (Hal – F, Br, I, At) to the specific conductivity of the NaCl melt. Between the numerical values of the specific electrical conductivity of the sodium astatide (NaAt) melt calculated by different methods, consistent data were obtained.

scholarly journals Температурные зависимости коэффициента термоэдс, удельного сопротивления и теплопроводности электронного и дырочного пирита FeS-=SUB=-2-=/SUB=- в интервале 293-400 K

2021 ◽  
Vol 55 (9) ◽  
pp. 826
Author(s):  
Н.П. Степанов ◽  
С.А. Немов ◽  
И.В. Свешников ◽  
Г.И. Грабко ◽  
А.Н. Власов ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Specific Electrical Conductivity ◽  
Thermoelectric Efficiency ◽  
Type Conductivity ◽  
Thermal Emf ◽  
Temperature Dependences ◽  
Natural Pyrite ◽  
Good Agreement

Abstract The temperature dependences of the thermal EMF, the specific electrical conductivity, and the specific thermal conductivity of samples of natural pyrite FeS2, with electronic and hole-type conductivity, are studied in the temperature range of 293−400 K. The data obtained are in good agreement with the results of previous studies of the electrical properties of this mineral, established in the course of geophysical studies. Based on the results of the performed measurements, as well as taking into account the known data on the temperature behavior of the thermo-EMF and the specific electrical conductivity of pyrite in the range of 300−700 K, estimates of its thermoelectric efficiency are mad

XII.—On the Electrical Conductivity of Aqueous Hydrochloric Acid, saturated with Sodium Chloride; and on a new form of Conductivity Cell

1915 ◽  
Vol 35 ◽  
pp. 138-145
Author(s):  
F. D. Miles
Keyword(s):  
Electrical Conductivity ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Hydrogen Chloride ◽  
Saturated Acid ◽  
Specific Conductivity ◽  
Specific Electrical Conductivity ◽  
Maximum Conductivity ◽  
New Form ◽  
Conductivity Cell

Summary(1) Determinations have been made, at 18° C, of:—(a) the specific electrical conductivity, (b) the percentage composition by weight, of a series of mixtures made by saturating, with sodium chloride, solutions of hydrochloric acid containing from 16 to 27 per cent, of hydrogen chloride.(2) Within this range of concentration the salt-saturated acid has lower specific conductivity than the aqueous solution of hydrogen chloride alone, from which it may be supposed to be derived. Of the salt-saturated acid mixtures, that one has maximum conductivity which could be prepared by adding salt to hydrochloric acid containing 2·9 per cent, of hydrogen chloride. Of solutions of hydrogen chloride alone, in water, that containing 19·1 per cent, hydrogen chloride has maximum conductivity.(3) The critical concentration of hydrogen chloride at which hydrochloric acid is able to affect the colour of cobalt chloride is changed, in the same sense as the concentration of hydrogen chloride corresponding to maximum conductivity is changed, by saturating the solution with salt.(4) A new form of conductivity cell is described. It is specially suitable for solutions which are saturated with dissolved solid, or contain a volatile solvent.

The physical properties of chromium oxide—aluminium oxide catalysts - II. Electrical properties

1954 ◽  
Vol 224 (1158) ◽  
pp. 419-426 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Physical Properties ◽  
Chromium Oxide ◽  
Electric Potential ◽  
Chromium Content ◽  
Aluminium Oxide ◽  
Oxide Catalysts ◽  
Thermo Electric ◽  
Alumina Catalysts

The electrical conductivity and thermo-electric potential of co-precipitated chromium oxide-alumina catalysts have been measured. The addition of alumina at first produces a rapid increase in the conductivity, but with higher concentrations of alumina this sub­sequently falls to values below that of chromium oxide alone. Catalysts reduced in hydrogen at 500°C are n -type semi-conductors if they contain more than about 35% of chromium oxide; those with lower chromium content, and all mixtures after heating in air, are p -type semi-conductors. Energies of activation for both types of conduction have been calculated.

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