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.

Studies on Polyaniline: Polyethyleneterephthalate Films

2006 ◽  
Vol 111 ◽  
pp. 99-102 ◽  
Author(s):  
A.A. Ahmed ◽  
Faiz Mohammad
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Arrhenius Equation ◽  
Great Increase ◽  
Thermooxidative Stability ◽  
Ambient Conditions ◽  
Dc Electrical Conductivity ◽  
The Stability ◽  
Almost All ◽  
Conductivity Retention

The films of polyaniline:polyethyleneterephthalate films were prepared by polymerizing aniline soaked in polyethyleneterephthalate films of different thicknesses. The films were characterized by FTIR as well as for their electrical properties. The electrical properties of the films were observed to be of good quality as almost all the films showed a great increase in their electrical conductivity from insulator to semiconductor region after doping with hydrochloric acid. All the films in their doped state follow the Arrhenius equation for the temperature dependence of electrical conductivity from 35 to 115oC. The thermooxidative stability was studied by thermogravimetry and differential thermal analysis. The stability in terms of dc electrical conductivity retention was also studied under ambient conditions by two slightly different techniques viz. isothermal and cyclic techniques. The dc electrical conductivity of the films was found to be stable below 90oC for all the films under ambient conditions.

scholarly journals INVESTIGATION OF ELECTRICAL CONDUCTION IN VANADATE BASED GLASSES

2013 ◽  
Vol 22 ◽  
pp. 255-260 ◽  
Author(s):  
R. V. BARDE ◽  
S. A. WAGHULEY
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Conduction ◽  
Arrhenius Equation ◽  
Localized States ◽  
Melt Quenching ◽  
Temperature Range ◽  
Dc Electrical Conductivity ◽  
Glassy Systems

The binary glassy systems 60V2O5-(40-x)P2O5 –xB2O3 were prepared by melt quenching technique. The mole of B2O3 was varies from 5 to 20 mol % with constant mol % of V2O5 during preparation of glass samples. The dc electrical conductivity of samples was measured in temperature range 303-473 K and found to be higher for sample 60 V2O5-20P2O5 –20B2O3 . Using the Arrhenius equation of conductivity, the activation energy of conduction is estimated. The conduction in these glasses is takes place by phonon-assisted hopping between the localized states.

scholarly journals Analysis of X-ray structure, dielectric properties and AC conductivity of (4E)-2-amino-3-cyanobenzo[b]oxocin-6-one

2016 ◽  
Vol 34 (2) ◽  
pp. 386-392 ◽  
Author(s):  
H.A.M. Ali ◽  
Magdy A. Ibrahim
Keyword(s):  
Crystal Structure ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Relaxation Time ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Different Temperatures

AbstractThe crystal structure of (4E)-2-amino-3-cyanobenzo[b]oxocin-6-one, denoted as 4(E)-ACBO, was analyzed using X-ray diffraction technique. The dielectric and AC electrical conductivity measurements of the bulk 4(E)-ACBO in the form of pellet were studied in the range of frequency 42 Hz to 5 MHz and the temperature range of 303 K to 373 K. The temperature and frequency dependence of dielectric constant (∊1), dielectric loss (∊2) and AC electrical conductivity (σAC) were investigated. The relaxation time (τ) for electrons to hop over a barrier of height WH was calculated at different temperatures. The AC activation energy was determined from the temperature dependence of σAC at different frequencies.

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).

scholarly journals Polaronic behavior of La0.8Te0.2MnO3

2013 ◽  
Vol 03 (04) ◽  
pp. 1320002
Author(s):  
Cene Filipič ◽  
Adrijan Levstik
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Theoretical Model ◽  
Charge Transport ◽  
Detailed Analysis ◽  
Dielectric Response ◽  
Charge Carriers ◽  
Published Data ◽  
Ac Electrical Conductivity ◽  
Small Polarons

We have analyzed recently published data of the ac electrical conductivity and dielectric constant in La 0.8 Te 0.2 MnO 3 (LTMO), and at temperatures below 500 K both quantities follow the universal dielectric response (UDR) typical of hopping or tunneling of localized charge carriers. A detailed analysis of the temperature dependence of the UDR parameter s in terms of the theoretical model for tunneling of small polarons revealed that below 500 K, this mechanism governs the charge transport in LTMO system.

scholarly journals Influence of High Conductive Magnetite Impurity on the Electrical Conductivity of Dry Olivine Aggregates at High Temperature and High Pressure

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 44 ◽  
Author(s):  
Lidong Dai ◽  
Haiying Hu ◽  
Wenqing Sun ◽  
Heping Li ◽  
Changcai Liu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
High Pressure ◽  
Percolation Threshold ◽  
Atmospheric Pressure ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Frequency Range ◽  
Arrhenius Relation ◽  
Conductivity Anomalies

The electrical conductivity of dry sintered olivine aggregates with various contents of magnetite (0, 3, 5, 7, 10, 20, and 100 vol. %) was measured at temperatures of 873–1273 K and a pressure of 2.0 GPa within a frequency range of 0.1–106 Hz. The changes of the electrical conductivity of the samples with temperature followed an Arrhenius relation. The electrical conductivity of the sintered olivine aggregates increased as the magnetite-bearing content increased, and the activation enthalpy decreased, accordingly. When the content of interconnected magnetite was higher than the percolation threshold (~5 vol. %), the electrical conductivity of the samples was markedly enhanced. As the pressure increased from 1.0 to 3.0 GPa, the electrical conductivity of the magnetite-free olivine aggregates decreased, whereas the electrical conductivity of the 5 vol. % magnetite-bearing sample increased. Furthermore, the activation energy and activation volume of the 5 vol. % magnetite-bearing sintered olivine aggregates at atmospheric pressure were calculated to be 0.16 ± 0.04 eV and −1.50 ± 0.04 cm3/mole respectively. Due to the high value of percolation threshold (~5 vol. %) in the magnetite impurity sample, our present results suggest that regional high conductivity anomalies in the deep Earth’s interior cannot be explained by the presence of the interconnected magnetite-bearing olivine aggregates.

scholarly journals Dielectric behavior and AC electrical conductivity analysis of PMMA films

2019 ◽  
Vol 11 (20) ◽  
pp. 47-57
Author(s):  
Bushra A. Hasan
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Casting Process ◽  
Intermolecular Forces ◽  
Dielectric Behavior ◽  
Ac Electrical Conductivity ◽  
Dielectric Constant And Loss ◽  
Conduction Behavior ◽  
Calculated Activation Energy

PMMA films of different thickness (0.006, 0.0105, 0.0206, 0.0385 and 0.056cm) were synthesized by casting process. The temperature and frequency dependence of dielectric constant and AC electrical conductivity measurements at various frequencies (10kHz-10MHz) and temperatures (293-373K) were carried out. Few anomalies in dielectric studies were observed near 313 and 373 K respectively. These points were related to glass transitions temperature. The variation of activation energy and conduction behavior was studied .From the AC conduction studies, it is confirmed that the mechanism responsible for the conduction process is hopping of carriers. The variations of the dielectric constant and loss as function of frequency at different temperature was observed and the results were discussed. The calculated activation energy varied with the thickness, temperature, and applied frequency. Conductivity plots against frequency suggested that the response obeying the universal power law concerning the AC conductivity and dielectric behavior of polymer. The polarizability a increases with temperature but decreases with thickness indicating weekends and rising of intermolecular forces respectively.

scholarly journals EFFECT OF CARBON NANOTUBES ON THE ELECTRICAL PROPERTIES OF THE POLYMERIC COMPOSITES

2019 ◽  
Vol 3 ◽  
pp. 45
Author(s):  
Sergey Gango ◽  
Konstantin Gusev ◽  
Evgeniy Ilin ◽  
Mikhail Predtechensky ◽  
Vladimir Solovyev ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Experimental Study ◽  
Electrical Properties ◽  
Polymeric Composite ◽  
Frequency Range ◽  
Ac Electrical Conductivity ◽  
Current Voltage ◽  
Temperature Dependences ◽  
Current Voltage Characteristics

Experimental study of single-wall carbon nabotubes (CNT) effect on the electrical properties of polymeric composite materials based on epoxy matrix has been carried out. Direct-current (DC) as well as alternating-current (AC) electrical conductivity of nanocomposites with different CNT concentrations have been investigated in the temperature interval from 293 K to 373 K. Measurements of Seebeck coefficient confirm n-type conductivity of composite with CNTs. Percolation threshold of the composite material under study has been estimated. It has been found that addition of single-wall CNT at low concentration causes hysteresis of current-voltage characteristics and the temperature dependences of electrical conductivity as well as its anisotropy in the samples under study. No noticeable frequency dependence of the AC electrical conductivity has been found in the frequency range from 100 Hz to 300 kHz.

scholarly journals Preparation and studying Structural and Electrical properties of nano Co3O4

2019 ◽  
Vol 24 (6) ◽  
pp. 126
Author(s):  
Nawar Thamer Mohammed ◽  
Wasfi Mohammed Kadem
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Sol Gel ◽  
Frequency Range ◽  
Nano Powder ◽  
Structural And Electrical Properties ◽  
Electrical And Dielectric Properties ◽  
Lcr Meter

In this study (Cobalt oxide) nano powder prepared using sol-gel method with a crystallite size 22 nm By testing XRD  and by matching with card (JCPDS) files No.( 00-042-1467). Electrical and dielectric properties like (Dielectric constant, resistivity, electrical conductivity) are studied by LCR meter with frequency range from (50 Hz) to (5 MHz ). It was noted that the resistivity and dielectric constant was decreasing while electrical conductivity increased with increased  frequency    http://dx.doi.org/10.25130/tjps.24.2019.118  

scholarly journals Electrical Conductivity and Dielectric Properties of Bulk Glass V2O5 (ZnO, PbO) SrO FeO

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
M. S. Aziz ◽  
A. G. Mostafa ◽  
A. M. Youssef ◽  
S. M. S. Youssif
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Dielectric Dispersion ◽  
Bulk Glass ◽  
Frequency Range ◽  
Glassy System ◽  
Dielectric Parameters

The AC conductivity and dielectric parameters of the glassy system of (70-x) V2O5· x(Zn/Pb)· 10SrO · 20FeO (x = 0, 5, 10, and 15) glasses have been investigated. The frequency and temperature dependence of dielectric constant (ε′) and dielectric loss (ε′′) is studied in the frequency range 100 Hz–5 MHz and in the temperature range 300–460 K. Dielectric dispersion is observed in all samples as Zn/Pb increase content in the (70-x)V2O5· x(Zn/Pb)·10SrO·20FeO systems. These results are explained on the basis of a Debye-type relaxation. It is also observed that the activation energy increases on increasing the Zn/Pb contents in this system.

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