Electrical Conductivity of Ammonium Heptamolybdate Solutions and the Calculation of Its Activation Energy

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but decreases by increasing Cu concentration.

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Electrical Conductivity of Magnesium Oxide/Molten Carbonate Eutectic Coexisting System

Zeitschrift für Naturforschung A ◽

10.1515/zna-2019-0109 ◽

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.

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Methanation on exfoliated and supported MoS2

Canadian Journal of Chemistry ◽

10.1139/v89-133 ◽

1989 ◽

Vol 67 (5) ◽

pp. 862-866 ◽

Cited By ~ 5

Author(s):

Guenter A. Scholz ◽

S. Roy Morrison

Keyword(s):

Activation Energy ◽

Carbon Monoxide ◽

Transition Metal Catalysts ◽

Surface Species ◽

Reaction Products ◽

Third Order ◽

Ammonium Heptamolybdate ◽

First Order ◽

Methanation Reaction ◽

Improved Performance

The methanation reaction on MoS2 exfoliated to a thickness of a few layers or less and adsorbed onto alumina is found to be very small. However, by calcining and resulfiding the exfoliated MoS2 catalysts, greatly improved performance is achieved that is at least equal to the commercial catalysts based on ammonium heptamolybdate. The creation of molybdenum oxysulflde surface species therefore appears to be a necessary step toward producing significant methanation rates with exfoliated and supported MoS2. The methanation products are almost exclusively CO2 and CH4, their mole ratios near unity, with otherwise only very much smaller amounts of longer chain hydrocarbons. The activation energy for methanation is generally observed to be near 100 kJ/mol, with the overall reaction being first order in the carbon monoxide concentration and third order in the hydrogen concentration. In contrast to the transition-metal catalysts, no water could be detected in the reaction products of the molybdenum based catalyst. Keywords: methanation reaction on MoS2, exfoliated and supported MoS2 as catalyst.

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SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF SOLID SOLUTIONS OF THE SYSTEM RbF-PbF2-SnF2

Ukrainian Chemistry Journal ◽

10.33609/0041-6045.85.5.2019.60-68 ◽

2019 ◽

Vol 85 (5) ◽

pp. 60-68

Author(s):

Yuliay Pogorenko ◽

Anatoliy Omel’chuk ◽

Roman Pshenichny ◽

Anton Nagornyi

Keyword(s):

Activation Energy ◽

Electrical Conductivity ◽

Temperature Dependence ◽

Solid Solutions ◽

Basic Structure ◽

Elementary Cell ◽

Initial Structure ◽

Fluoride Ions ◽

Temperature Range ◽

Order Of Magnitude

In the system RbF–PbF2–SnF2 are formed solid solutions of the heterovalent substitution RbxPb0,86‑xSn1,14F4-x (0 < x ≤ 0,2) with structure of β–PbSnF4. At x > 0,2 on the X-ray diffractograms, in addition to the basic structure, additional peaks are recorded that do not correspond to the reflexes of the individual fluorides and can indicate the formation of a mixture of solid solutions of different composition. For single-phase solid solutions, the calculated parameters of the crystal lattice are satisfactorily described by the Vegard rule. The introduction of ions of Rb+ into the initial structure leads to an increase in the parameter a of the elementary cell from 5.967 for x = 0 to 5.970 for x = 0.20. The replacement of a part of leads ions to rubium ions an increase in electrical conductivity compared with β–PbSnF4 and Pb0.86Sn1.14F4. Insignificant substitution (up to 3.0 mol%) of ions Pb2+ at Rb+ at T<500 K per order of magnitude reduces the conductivity of the samples obtained, while the nature of its temperature dependence is similar to the temperature dependence of the conductivity of the sample β-PbSnF4. By replacing 5 mol. % of ions with Pb2+ on Rb+, the fluoride ion conductivity at T> 450 K is higher than the conductivity of the initial sample Pb0,86Sn1,14F4 and at temperatures below 450 K by an order of magnitude smaller. With further increase in the content of RbF the electrical conductivity of the samples increases throughout the temperature range, reaching the maximum values at x≥0.15 (σ573 = 0.34–0.41 S/cm, Ea = 0.16 eV and σ373 = (5.34–8.16)•10-2 S/cm, Ea = 0.48–0.51 eV, respectively). In the general case, the replacement of a part of the ions of Pb2+ with Rb+ to an increase in the electrical conductivity of the samples throughout the temperature range. The activation energy of conductivity with an increase in the content of RbF in the low-temperature region in the general case increases, and at temperatures above 400 K is inversely proportional decreasing. The nature of the dependence of the activation energy on the concentration of the heterovalent substituent and its value indicate that the conductivity of the samples obtained increases with an increase in the vacancies of fluoride ions in the structure of the solid solutions.

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The effect of additives metal on the D.C conductivity of epoxy resin

Baghdad Science Journal ◽

10.21123/bsj.8.1.168-174 ◽

2011 ◽

Vol 8 (1) ◽

pp. 168-174

Author(s):

Baghdad Science Journal

Keyword(s):

Activation Energy ◽

Electrical Conductivity ◽

Epoxy Resin ◽

Filler Content ◽

Experimental Results ◽

Filler Concentration ◽

Effect Of Additives

The present studies are focused on the modification of the properties of epoxy resin with different additives namely aluminum, copper by preparing of composites systems with percentage (20%, 40% and 50%) of the above additives. The experimental results show that the D.C of conductivity on wt% filler content at ( 293-413 ) K electrical conductivity of all above composites increased with temperature for composites with filler contact and find the excellent electrical conductivity of copper and lie between (2.6*10-10 - 2.1*10-10)?.cm . The activation energy of the electrical conductivity is determined and found to decrease with increasing the filler concentration.

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Transport and Meyer-Neldel Rule in Microcrystalline Silicon Films

MRS Proceedings ◽

10.1557/proc-862-a5.6 ◽

2005 ◽

Vol 862 ◽

Cited By ~ 4

Author(s):

Steve Reynolds ◽

Vlad Smirnov ◽

Friedhelm Finger ◽

Charlie Main ◽

Reinhard Carius

Keyword(s):

Activation Energy ◽

Electrical Conductivity ◽

Thermal Activation ◽

Prolonged Exposure ◽

Oxygen Adsorption ◽

Thermal Activation Energy ◽

Silicon Films ◽

Transport Mechanisms ◽

Microcrystalline Silicon ◽

Porous Films

AbstractChanges in the electrical conductivity of thin (< 300 nm) silicon films following prolonged exposure to atmosphere, are reported. Both reversible (by annealing at 150 °C under vacuum) and irreversible (annealing-resistant) effects are found to occur, which are larger in thinner films. The conductivity prefactor and thermal activation energy obey the Meyer-Neldel rule, although detailed behaviour depends on film thickness and microstructure. Irreversible changes may result from oxidation of thinner, more porous films, with water and/or oxygen adsorption and desorption responsible for reversible changes. The need to identify and account for these effects when discussing and formulating transport mechanisms in these materials is underlined.

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Internal Schottky barriers in semiconductors

Canadian Journal of Physics ◽

10.1139/p82-034 ◽

1982 ◽

Vol 60 (3) ◽

pp. 269-272 ◽

Cited By ~ 3

Author(s):

F. L. Weichman

Keyword(s):

Activation Energy ◽

Electrical Conductivity ◽

Cuprous Oxide ◽

Schottky Barriers ◽

Conduction Process ◽

Variable Activation Energy ◽

Semiconductor Contact

We discuss the effect on the electrical conductivity of a semiconductor if small metal inclusions are formed within the bulk of the semiconductor where the metal to semiconductor contact is a rectifying one. We find that the depletion layers formed inside the material can dominate the conduction process and give rise to conditions similar to that of a highly compensated semiconductor with highly variable activation energy. Some of the predictions of the model are compared to observed facts in cuprous oxide and are shown to be consistent with observation. The expected behaviour of a semiconductor with internal injecting contacts is also briefly discussed.

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Notizen: Fluorine Diffusion and Phase Transition in Superionic Conductor KSn2F5 as Studied by 19F NMR, Electrical Conductivity and DSC

Zeitschrift für Naturforschung A ◽

10.1515/zna-1983-0522 ◽

1983 ◽

Vol 38 (5) ◽

pp. 593-594 ◽

Cited By ~ 3

Author(s):

W. D. Basler ◽

I. V. Murin ◽

S. V. Chernov

Keyword(s):

Magnetic Field ◽

Phase Transition ◽

Activation Energy ◽

Electrical Conductivity ◽

Relaxation Time ◽

Field Gradient ◽

Magnetic Field Gradient ◽

Pulsed Magnetic Field ◽

19F Nmr ◽

Sharp Transition

The diffusion of fluorine in KSn2F5 has been studied by T1 and T2 relaxation time measurements of 19F NMR (200-500 K) and pulsed magnetic Field gradient techniques (390-480 K). Near 423 K a sharp transition into the superionic state has been found, the fluorine diffusion increasing by a factor of 4 within a range of 3 K. Conductivity measurements only show a change in the activation energy.

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Structural and electrical investigation of (Ag3AsS3)x(As2S3)1−x superionic glasses

Open Physics ◽

10.2478/s11534-011-0084-6 ◽

2012 ◽

Vol 10 (1) ◽

Cited By ~ 7

Author(s):

Ihor Studenyak ◽

Yuriy Neimet ◽

Csaba Cserháti ◽

Sándor Kökényesi ◽

Edvardas Kazakevičius ◽

...

Keyword(s):

Electron Microscopy ◽

Activation Energy ◽

Electrical Conductivity ◽

Scanning Electron Microscopy ◽

Transmission Coefficient ◽

Structural Studies ◽

Compositional Range ◽

Electrical Investigation ◽

Scanning Electron

AbstractStructural studies of (Ag3AsS3)x (As2S3)1−x chalcogenide superionic glasses in the compositional range x = 0.3–0.9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient, electrical conductivity, and activation energy were investigated

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Temperature and Composition Dependence of Electrical Conductivity of Ge10 Se90-x Bix (x=0, 2, 4, 6, 8, 10) Chalcogenide Glasses

SAMRIDDHI A Journal of Physical Sciences Engineering and Technology ◽

10.18090/samriddhi.v3i1.1610 ◽

2015 ◽

Vol 3 (1) ◽

Author(s):

Shiveom Srivastava ◽

S. K. Srivastava ◽

Krishna K. Srivastava ◽

Narayan P. Srivastava

Keyword(s):

Activation Energy ◽

Electrical Conductivity ◽

Chalcogenide Glasses ◽

Conduction Mechanism ◽

Composition Dependence ◽

Arrhenius Equation ◽

Atomic Weight ◽

Melt Quenching ◽

Characteristic Curves ◽

Glassy Systems

Electrical conductivity of Ge10 Se90-x Bix (x=0,2,4,6,8,10) glassy systems prepared by melt quenching technique has been studied at different temperature in bulk form through I-V characteristic curves. It has been observed that the electrical conductivity increases as the Bi concentration increases up to 4 atomic weight percentages and on further addition of Bi it reduces. The variation in electrical conductivity with Bi concentration is attributed to the Se-Bi bond concentration. Using the Arrhenius equation of conductivity, the activation energy of conduction is evaluated. The effect of Bi concentration on activation energy has also been studied. It is quite evident from results that Poole-Frankel and Rechardson-Schottky conduction mechanism hold good for conduction in these glasses.

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