Composition-Dependent Electrical Conductivity of Ionic-Electronic Composite

1997 ◽  
Vol 500 ◽  
Author(s):  
M. Park ◽  
G. M. Choi
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Electromotive Force ◽  
Composition Dependence ◽  
Force Measurement ◽  
Ionic Transport ◽  
Charge Carriers ◽  
Stabilized Zirconia ◽  
Ionic Charge ◽  
Polarization Technique

ABSTRACTComposition. dependence of electrical conductivity of ionic-electronic composite was camined using yttria(8mol%) stabilized zirconia-NiO composites. The contributions of ectronic and ionic charge carriers to the electrical conductivity were determined by Hebb-Vagner polarization technique and electromotive force measurement of galvanic cell. Up to 6 sol% NiO addition, the conductivity decreased since the electronic NiO acted as an insulator in onic matrix. However the ionic transport was dominant until NiO content reaches 26 vol%. Mixed conduction was observed between 26 and 68 vol% of NiO. The effects of composition on he electrical properties were explained by the microstructure and thus by the distribution of two hases.

THE ELECTRICAL PROPERTIES OF ALUMINA AT HIGH TEMPERATURES

1966 ◽  
Vol 44 (8) ◽  
pp. 1685-1698 ◽  
Author(s):  
T. Matsumura
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Single Crystal ◽  
Transport Number ◽  
Ionic Transport ◽  
Mixed Conductor ◽  
Polycrystalline Alumina ◽  
Ionic Transport Number

The ionic transport number and the d-c. electrical conductivity of single-crystal and polycrystalline alumina have been studied between 1 000 °K and 1 750 °K at an oxygen partial pressure of 0.2 atm. The ionic transport number was determined by the galvanic-cell e.m.f. measurements; the electrical conductivity was measured by the three-terminal method.It was found that alumina is a mixed conductor, being predominantly an ionic conductor at temperatures below 1 100 °K and predominantly electronic at temperatures higher than 1 600 °K. The activation energies found for the electrical conductivity of the single-crystal and polycrystalline specimens are 0.8 eV and 2.4 eV respectively in the ionic range and 3.0 eV and 3.7 eV in the electronic range.

Effect of HCl Concentration and Acetone Washing on the Dielectric and Conduction Properties of Polyaniline Salts

2021 ◽  
Vol 14 ◽  
Author(s):  
Jayashree Mohanty ◽  
S.R. Mishra ◽  
Tanmaya Badapanda ◽  
S. Anwar
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Acid Concentration ◽  
Charge Carriers ◽  
Short Chain ◽  
Water Medium ◽  
Distilled Water ◽  
Chain Polymer ◽  
Pani Salt ◽  
Long Chain

Aims: The aim of the work is to study the effect of acid concentration and acetone washing on electrical properties of Polyaniline (PANI) salts prepared through chemically oxidative polymerization. Background: The frequency dependent conductivity and dielectric permittivity provide important information on the electrical properties of conducting polymers which gives information regarding their utility in electronic applications. Objective: Hence, the present study is based on the comparative the electrical properties study (dielectric and electrical conductivity) of PANI salts prepared in two different media like water and 1M HCl along with study regarding effect acetone washing on the said electrical properties of the polymer samples. Methods: PANI salts are synthesized through chemical oxidative polymerisation of aniline hydrochloride with the oxidant ammonium persulphate in two different media like water and 1M HCl. One part of the PANI salt samples were washed with distilled water after synthesis and another part of the polymer samples were washed with distilled water followed by acetone to study the effect of acetone washing on the electrical properties of polymer samples. Results: Non-acetone washed PANI salt prepared in water medium shows the highest dielectric as well as electrical conductivity due to the increased charge carriers provided both by long chain polymer as well as short chain oligomers. When the acid concentration is increased to 1M there may be loss of protons accompanied by pairing of free radicals to form quinoimine units that leads to the loss of charge carriers consequently decreasing the dielectric constant and electrical conductivity. Conclusion : PANI salt prepared in water shows the highest dielectric as well as conductivity due to the increased charge carriers provided both by long chain polymer as well as short chain oligomers.

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).

Zircontes/Sulfates Composites: Perfect Combination of High- and Low-Temperature Protonic Conductors

2010 ◽  
Vol 434-435 ◽  
pp. 719-722
Author(s):  
Zhen Zhen Peng ◽  
Rui Song Guo ◽  
Zi Guang Yin ◽  
Juan Li
Keyword(s):  
Electrical Conductivity ◽  
Fuel Cell ◽  
Low Temperature ◽  
Electromotive Force ◽  
Ionic Transport ◽  
Proton Conductors ◽  
Transport Numbers ◽  
Barium Zirconate ◽  
Emf Measurements ◽  
Protonic Conductors

Two typical classes of proton conductors, zirconates and solid acids (such as CsHSO4) or related sulfates, are intensively investigated recently. Based on the different proton-conducting mechanisms of zirconates and sulfates, we designed and fabricated Y2O3-doped barium zirconate/sulfates composites, aiming to make full use of the benefits, and eliminate the drawbacks of the two individual materials. The electrical conduction of the composite was studied by electrical and electrochemical methods. Microstructure of the composites was examined by SEM. Electromotive force (EMF) measurements were conducted under fuel cell conditions. The results indicated that small amount of sulfates was introduced at the grain boundaries of BaZr0.9Y0.1O2.95. The electrical conductivity of the composites was greatly improved and the total ionic transport numbers of the composites are more than 0.9 at 750 °C.

Microstructural Aspects of the Ionic Transport Properties of Strontium-Substituted Lanthanum Cobaltites

2002 ◽  
Vol 756 ◽  
Author(s):  
W. Sitte ◽  
E. Bucher ◽  
W. Preis ◽  
I. Papst ◽  
W. Grogger ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Charge Carriers ◽  
Log P ◽  
Conductivity Measurements ◽  
Ionic Charge ◽  
Galvanostatic Polarization ◽  
Vacancy Ordering ◽  
Polarization Technique ◽  
Electron Microscopical ◽  
Distinct Maximum

ABSTRACTThe ionic conductivity and microstructure of selected compositions of the solid solution La1-xSrxCoO3-δ (LSC) were examined with respect to possible vacancy ordering phenomena. Homogeneous samples of LSC were prepared by the glycine nitrate process. The ionic conductivity was obtained as a function of the oxygen partial pressure (-3.5 ≤ log[p(O2)/atm] ≤ 0.5) using a recently developed galvanostatic polarization technique. At 825°C the p(O2)-dependence of the ionic conductivity of La1-xSrxCoO3-° (x = 0.4 and 0.6) shows a distinct maximum. Although this behavior has yet to be explained unambiguously it is indicative of decreasing mobility of ionic charge carriers, e. g. due to cooperative vacancy ordering. From the temperature dependence of the ionic conductivity of La1-xSrxCoO3-° (x = 0.6) activation energies at constant nonstoichiometry (0.20 ≤ ° ≤ 0.28) were obtained. As vacancy association and microstructure are presumed to play a significant role we combined the results of ionic conductivity measurements and electron microscopical investigations. HRTEM images revealed a superstructure within microdomains of about 100 nm in size.

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.

High Electrical Conductivity in Organic Single-Component Systems Based on 2,5-Dimethylthio-TCNQ

1993 ◽  
Vol 328 ◽  
Author(s):  
J. S. Zambounis ◽  
J. Mizuguchi ◽  
H. Hediger ◽  
J. Pfeiffer ◽  
B. Schmidhalter ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Room Temperature ◽  
Single Component ◽  
Charge Carriers ◽  
Optical And Electrical Properties ◽  
High Electrical Conductivity ◽  
Component System ◽  
Component Systems ◽  
Neighboring Molecule

ABSTRACT2,5-dimethylthio-TCNQ has been newly synthesized, and its optical and electrical properties have been investigated in evaporated films. A high electrical conductivity of σ=2× 10−5 Scm−l has been measured at room temperature. The present single-component system is found to contain 2×1017 spins/cm3. The charge carriers are presumably due to incorporated impurities which give the ESR signals. Carrier hopping is considerably facilitated by close intermolecular S-N contacts between the S atom of the -SCH3 group of one molecule and the N atom of -C≡N group of the neighboring Molecule.

Composition Dependence of The Electrical Conductivity of n-p Ceramic Composite

1994 ◽  
Vol 357 ◽  
Author(s):  
Seok-Taek Jun ◽  
Gyeong-Man Choi
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Grain Boundaries ◽  
Ceramic Composite ◽  
Composition Dependence ◽  
Volume Fraction ◽  
Ceramic Composites ◽  
Equivalent Circuits ◽  
Total Resistance ◽  
Impedance Response

AbstractElectrical properties of ZnO-CuO ceramic composites with varying composition were investigated. The electrical conductivity increased with increasing CuO volume fraction between 1 mol% to 95 mol%. Impedance response showed three semicircles, indicating three resistive elements contributing to the total resistance of the composite. A new model based on the equivalent circuits was developed to explain the contribution of grain boundaries to the resistance of the composite. The change of electrical conductivity was explained by the probability change of two equivalent circuits.

scholarly journals Thermodynamic properties of the liquid Bi-Cu-Sn lead-free solder alloys

2009 ◽  
Vol 45 (1) ◽  
pp. 95-100 ◽  
Author(s):  
M. Kopyto ◽  
G. Garzel ◽  
L.A. Zabdyr
Keyword(s):  
Thermodynamic Properties ◽  
Cross Sections ◽  
Electromotive Force ◽  
Force Measurement ◽  
Yttria Stabilized Zirconia ◽  
Lead Free Solder ◽  
Stabilized Zirconia ◽  
Galvanic Cells ◽  
Free Solder ◽  
Tin Content

The electromotive force measurement method was employed to determine the thermodynamic properties of liquid Bi-Cu-Sn alloys using solid electrolyte galvanic cells as shown below: Kanthal+Re, Bi-Cu-Sn, SnO2 | Yttria Stabilized Zirconia | air, Pt, Po2=0.2:1 atm Measurements were carried out for three cross-sections with constant Bi/Cu ratio equal to: 1/3, 1 and 3 and for various tin content varying every 10%, resulting in a total of 26 different alloy compositions. The temperature of the measurements varied within the range from 973 to 1325 K. A linear dependence of the e.m.f. on temperature was observed for all alloy compositions and the appropriate line equations were derived. Tin activities were calculated as function of composition and temperature. Results were presented in tables and figures.

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

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