Electrochemical and electrical properties of. Nb- and/or C-containing LiFePO4 composites

2004 ◽  
Vol 835 ◽  
Author(s):  
C. Delacourt ◽  
C. Wurm ◽  
L. Laffont ◽  
F. Sauvage ◽  
J.-B. Leriche ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Synthesis Conditions ◽  
Total Electrical Conductivity ◽  
In Doping ◽  
P Matrix

AbstractLiFePO4-based powders prepared through various synthesis conditions are presented. Depending on whether the precursors contain carbon or not, LiFePO4-based composites obtained contain significant amounts of carbon as well. We did not succeed in doping LiFePO4 with Nb and produced, instead, crystalline β-NbOPO4 and/or an amorphous (Nb, Fe, C, O, P) matrix around LiFePO4 particles. The total electrical conductivity is of ∼10−9 S.cm−1 at 25°C with an activation energy of ca. 0.65 eV for pure LiFePO4 and LiFePO4/β-NbOPO4 composite. C-containing LiFePO4 samples, including those that had been tentatively doped with Nb, are much more conductive (up to 1.6.10−1 S.cm−1) with an activation energy ΔE ∼ 0.08 eV.

scholarly journals Preparation and Study of some Electrical Properties of PVA-Ni(NO3)2 Composites

2014 ◽  
Vol 40 ◽  
pp. 36-42 ◽  
Author(s):  
Sabah A. Salman ◽  
Nabeel A. Bakr ◽  
Mohammed H. Mahmood
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Filler Content ◽  
Experimental Results ◽  
Casting Technique ◽  
Different Temperatures

The aim of this paper is to prepare and study the (D.C.) electrical conductivity of (PVA-Ni (NO3)2) composites at different temperatures. For that purpose, PVA films with Ni (NO3)2 salt additive were prepared with different concentrations‎ 2, 4, 6, 8 and 10 wt. % and with thickness of 45μm by using casting technique. The experimental results for PVA-Ni (NO3)2) ‎films show that the (D.C.) electrical‏ ‏conductivity increased with increasing ‎the filler content and the‏ ‏temperature, and the activation energy was ‎decreased with increasing the filler content‎.

Chalcogenide Glasses

MRS Bulletin ◽  
1987 ◽  
Vol 12 (5) ◽  
pp. 36-39 ◽  
Author(s):  
P. Craig Taylor
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Periodic Table ◽  
Chalcogenide Glasses ◽  
Charge Carriers ◽  
Arsenic Trisulfide ◽  
Glass Forming ◽  
Optical Gap ◽  
Arsenic Triselenide

Although there are some significant exceptions, most important glass-forming systems contain elements from the sixth, or chalcogenide, column of the periodic table (oxygen, sulfur, selenium, or tellurium). The glasses which contain oxygen are typically insulators, while those which contain the heavier chalcogen elements are usually semiconductors. Even though oxygen is technically a chalcogen element, the term “chalcogenide glass” is commonly used to denote those largely covalent, semiconducting glasses which contain sulfur, selenium, or tellurium as one of the constituents.The chalcogenide glasses are called semiconducting glasses because of their electrical properties. The electrical conductivity in these glasses depends exponentially on the temperature with an activation energy which is approximately one half of the optical gap. In this sense these glasses exhibit electrical properties similar to those in intrinsic crystalline semiconductors. The analogy is by no means perfect. The mobilities for the charge carriers in these glasses are very low (< 10 cm2/V-s) compared to crystalline semiconductors, and there are even discrepancies in determining the sign of the charge carriers from measurements of the Hall effect and the Seebeck effect.The first detailed studies of the chalcogenide glasses were performed about 30 years ago. For many years the prototype compositions have been selenium (Se), arsenic triselenide (As2Se3) or arsenic trisulfide (As2S3), and germanium diselenide (GeSe2) or germanium disulfide (GeS2).

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.

scholarly journals "Effect of Doping on Electrical Properties of Nickel Oxide (NPs) Prepared by Pulse Nd-Yag Laser Deposition Method "

2020 ◽  
Vol 8 (1) ◽  
pp. 130-134
Author(s):  
Rasha Hamid Ahmed
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Nickel Oxide ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Iron Cobalt ◽  
Yag Laser ◽  
Glass Substrates ◽  
Temperature Ranges

"In this study, nickel oxide (NPs) films were produced by doping each element with 2% zinc, tin, iron, cobalt and magnesium. pulsed laser deposition was used to deposit them on glass substrates , and we used a pulsed Nd-YAG laser with a wavelength of 1064nm. All the films were annealed with one temperature (573k). The electrical properties of the prepared films were studied, such as the continuous electrical conductivity and activation energy, and we found that increasing the temperature increases the electrical conductivity values Also, the value of the electrical conductivity and the activation energy change according to the type of added doping. We also discovered many activation energy values in the temperature ranges of (308K-428K) , and observed the conduct of nanoparticle oxide doping with various metals at these temperatures.

scholarly journals The Study of The Electrical Conductivity and Activation Energy on Conductive Polymer Materials

2021 ◽  
Vol 4 (2) ◽  
pp. 71
Author(s):  
Balqyz Lovelila Hermansyah Azari ◽  
Totok Wicaksono ◽  
Jihan Febryan Damayanti ◽  
Dheananda Fyora Hermansyah Azari
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Activated Carbon ◽  
Electrical Properties ◽  
Mass Fraction ◽  
Conductive Polymers ◽  
Conductive Polymer ◽  
Conductivity Measurement ◽  
Polymer Materials ◽  
Electrical Conductivity Measurement

Conductive Polymers are one of the interesting topics to be developed in recent years. Conductive polymers can combine the properties of polymers and the electrical properties of metals. Research related to the electrical properties of conductive polymers, including electrical conductivity measurements and determination of activation energy has been carried out. This study aims to determine the effect of addition mass fraction of activated carbon into the nylon polymer on the conductive polymer material based on the electrical conductivity and activation energy. The variations of activated carbon used are 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% (wt/V). The conductive polymer from nylon polymer and activated carbon is made by casting solution method. The electrical conductivity measurement of the conductive polymer and the activation energy was carried out using the parallel plate method. The value of electrical conductivity increased from 5.62×10-9 ± 1.89×10-10 S/cm for the pure nylon to 2.51×10-8 ± 2.87×10-10 S/cm for the addition of mass fraction of activated carbon 8% wt/V. Meanwhile, there was a decrease in the addition of 9% wt/V and 10% wt/V of mass fraction of activated carbon, which were 2.36×10-8 ± 3.47×10-10 S/cm and 2.28×10-8 ± 4.01×10-10 S/cm. The activation energy of conductive polymer obtained decreased with increasing in the mass fraction of the activated carbon into the nylon polymer. The activation energy for the pure nylon was 0.0189 eV and 0.0127 eV for the addition of 8% wt/V mass fraction of activated carbon. Meanwhile, there was an increase in the addition of 9% wt/V and 10% wt/V mass fractions of activated carbon of 0.0145 eV and 0.0150 eV, respectively.

scholarly journals Dependence of Electrical Properties on Frequency and Temperature for Novel Cyclopentenone Derivatives

2020 ◽  
Vol 1 (1) ◽  
pp. 13-25
Author(s):  
Salama A. H.
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Arrhenius Equation ◽  
Charge Carriers ◽  
Frequency Range ◽  
Ac Electrical Conductivity ◽  
Dc Electrical Conductivity ◽  
Arrhenius Relation

Electrical properties of some new cyclopentenone derivatives have been studied. The structures of prepared samples were characterized by (UV), (XRD) and (SEM). The dependence of electrical properties such as σdc , σac , ɛ' and ɛ'' on frequency and temperature were studied at frequency range from 50 Hz to 5 MHz and the temperature range from 25oC to 140oC. It was found that, ɛ' decreased with increasing frequency while it increases with increasing temperatures within the used ranges. Moreover, dielectric constant is structural dependent which is obvious from the variation of dielectric constant for each sample. Ac-electrical conductivity increased with increasing frequency which was attributed to the polarization of the charge carriers. The temperature dependence of dc-electrical conductivity show typical Arrhenius relation for the three prepared samples. The activation energy calculated from Arrhenius equation and the results are discussed in detailed.

scholarly journals Electrical Conductivity Studies of Composites Based on (Cu1–xAgx)7GeSe5I Solid Solutions

2020 ◽  
Vol 65 (1) ◽  
pp. 55
Author(s):  
A. I. Pogodin ◽  
M. M. Luchynets ◽  
V. I. Studenyak ◽  
O. P. Kokhan ◽  
I. P. Studenyak ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Impedance Spectroscopy ◽  
Solid Solutions ◽  
Frequency Range ◽  
Total Electrical Conductivity ◽  
Cationic Substitution ◽  
Nyquist Plots ◽  
Ionic Components ◽  
Frequency Dependences

Polymer composites based on (Cu1−xAgx)7GeSe5I solid solutions are produced. The electrical conductivity of the composites is measured by impedance spectroscopy in the frequency range from 20 Hz to 2×106 Hz and in the temperature interval 292–338 K. The frequency dependences of the total electrical conductivity are obtained, the Nyquist plots are constructed, and their analysis is performed. The effect of Cu+ →Ag+ cationic substitution on the total electrical conductivity and the activation energy, as well as on the electronic and ionic components of the electrical conductivity of composites based on (Cu1−xAgx)7GeSe5I solid solutions is studied on the basis of compositional dependences.

scholarly journals Semiconducting properties of nonstoichiometric TiO2-x ceramics

2012 ◽  
Vol 6 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Agnese Pura ◽  
Kristaps Rubenis ◽  
Dmitrijs Stepanovs ◽  
Liga Berzina-Cimdina ◽  
Jurijs Ozolins
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Room Temperature ◽  
High Vacuum ◽  
Titanium Oxides ◽  
Atmospheric Conditions ◽  
Semiconducting Properties ◽  
Two Stages ◽  
Extrusion Technology

Ceramics containing titanium oxides were prepared using extrusion technology and thermal treatment in two stages: sintering at normal atmospheric conditions at 1000 and 1200?C and annealing in high vacuum conditions at 950 and 1150?C. Electrical properties such as thermopower and electrical conductivity of cylindrical specimens have been studied at temperature range from the room temperature up to 350?C. Activation energy of the process has been determined from conductivity curves. Obtained thermopower values are in the range from 68 up to 105 mV at temperature gradient between the hot and cold ends of the samples at 300?C, while activation energy values are from 0.03 to 1.16 eV.

Notizen: Electrical Conduction in Thioxanthene

1976 ◽  
Vol 31 (9) ◽  
pp. 1301-1302
Author(s):  
S. Pietra ◽  
A. Tenaglia
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Single Crystals ◽  
Electrical Conduction

Electrical conductivity of thioxanthene single crystals has been observed. The electrons, injected from the electrodes or freed by sulphur atoms, are responsible for the electrical properties. The activation energy for the conduction is higher than in thianthrene, it depends maybe on the number of S atoms in the molecule.

The Peculiarities of the Electrical Conductivity of LiNbO3 Crystals, Reduced in Hydrogen

2013 ◽  
Vol 200 ◽  
pp. 193-198 ◽  
Author(s):  
Aleksandr V. Yatsenko ◽  
A.S. Pritulenko ◽  
S.V. Yevdokimov ◽  
Dmytro Yu. Sugak ◽  
I.M. Solskii
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Lithium Niobate ◽  
Low Frequency ◽  
Spectroscopy Method ◽  
Surface Layers ◽  
Temperature Range ◽  
Conductivity Mechanism

The low-frequency impedance spectroscopy method has been used to investigate the electrical conductivity peculiarities of lithium niobate (LN) crystals reduced in hydrogen. It has been found that the activation energy value of the dark electrical conductivity of such crystals in a temperature range of 288...370 К is equal to 0.68±0.02 eV. It has been demonstrated that the multiple heating of «black» LN crystals up to a temperature of about 420 K results in surface layers with modified electrical properties to occur in the crystal’s polar faces. The electrical conductivity mechanism of LiNbO3 crystals reduced in the hydrogen-containing atmosphere, and the causes of the instability of these properties are discussed.

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