Electrical Conductivity in (Gdl-xCax)2Sn2O7±δ Pyrochlore System

1994 ◽  
Vol 369 ◽  
Author(s):  
Tae-Hwan Yu ◽  
Harry L. Tuller
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Oxygen Vacancy ◽  
Doping Concentration ◽  
Migration Energy ◽  
Conductivity Measurements ◽  
Ca Doping ◽  
Pyrochlore Compounds ◽  
Cation Radius ◽  
High Level

AbstractElectrical conductivity measurements were performed on Gd2Sn207 as a function of temperature, P02 and Ca doping concentration. An effective frenkel constant and oxygen vacancy mobility were derived. The high level of intrinsic anion disorder found in this study is consistent with expectations based on the cation radius ratio (rA/rB) which was earlier found to be important in determining anion disorder in A2B207 pyrochlore compounds [1]. The magnitude of the ionic conductivity in Gd2Sn2O7 was found to be depressed relative to Gd2(Til-xZrx)207 based systems due to a high oxygen vacancy migration energy.

Novel lithium and sodium salts of sulfonamides and bis(sulfonyl)imides: synthesis and electrical conductivity

2014 ◽  
Vol 38 (12) ◽  
pp. 6193-6197 ◽  
Author(s):  
Vincent Morizur ◽  
Sandra Olivero ◽  
Jean Roger Desmurs ◽  
Philippe Knauth ◽  
Elisabet Duñach
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Conductivity Measurements ◽  
Sodium Salts

Ionic conductivity measurements were performed on a series of lithium and sodium salts and conductivities of 0.20 to 0.51 mS cm−1 were obtained.

scholarly journals Synthesis ofβ-Phase (Bi2O3)1-x(Dy2O3)x(0.01

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Serdar Yilmaz ◽  
Orhan Turkoglu ◽  
Ibrahim Belenli
Keyword(s):  
Phase Transition ◽  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Doping Concentration ◽  
Unit Cell Parameters ◽  
Oxygen Conductivity ◽  
Cell Parameters ◽  
Conductivity Curve ◽  
Phase Systems ◽  
Regular Increase

β-phase (Bi2O3)1-x(Dy2O3)xsystem with tetragonal structure is synthesized for0.01<x<0.10molar doping. Unit cell parameters increased with increasing the doping. We have studied the dependence of total electrical conductvity on temperature, doping concentration ofβ-phase systems. The phase transition which manifests itself by the jump in the conductivity curve was also verified by DTA and both measurements are rather compatible. The electrical conductivity curves ofβ-phase structure revealed regular increase in the form of an Arrhenius curve. The activation energies are calculated from these graphs.Bi2O3-basedDy2O3doped ceramics show ionic oxygen conductivity. The conductivity increased as the doping concentration increased. The highest value of conductivity is 0.006 0.006ohm-1cm-1(600∘C)for theβ-phase (Bi2O3)0.91(Dy2O3)0.09(800∘C). The sample with the highest conductivity is (Bi2O3)0.91(Dy2O3)0.09(800∘C)binary system where 1.450 ohm−1cm−1(745∘C).

Total Body Electrical Conductivity Measurements in the Neonate

1991 ◽  
Vol 18 (3) ◽  
pp. 611-627 ◽  
Author(s):  
Marta L. Fiorotto ◽  
William J. Klish
Keyword(s):  
Electrical Conductivity ◽  
Conductivity Measurements ◽  
Total Body

Characterization of New Ionically Conducting Peo-Based Networks by Diffusion, Elasticity Modulus and Ionic Conductivity Measurements

1992 ◽  
Vol 293 ◽  
Author(s):  
Herve Cheradame ◽  
F. Desbat ◽  
P. Mercier-Niddam ◽  
S. Boileau
Keyword(s):  
Diffusion Coefficient ◽  
Ionic Conductivity ◽  
Elasticity Modulus ◽  
Sol Gel ◽  
Cation Transport ◽  
Lithium Cation ◽  
Conductivity Measurements ◽  
Conducting Materials ◽  
Diffusion Studies

AbstractIonically conducting materials containing PEO were prepared from telechelic di(methyl-diethoxy-silane) PEO, synthesized by the hydrosilylation of telechelic diallyl-PEO with methyldiethoxysilane. The network is obtained by the usual sol-gel chemistry. Then, it is filled with LiClO4 by diffusion of the salt and further drying. A comparison is made with the same kind of materials crosslinked using urethane chemistry. Diffusion studies show that the diffusion coefficient of solvent is similar for both types of materials, whilst the ionic conductivity is higher for the networks crosslinked with siloxane bonds. An experiment of diffusion of LiClO4 without solvent showed that this salt has a diffusion coefficient of the order of 2.10-8 cm2.sec-1 at 34°C. The conductivity calculated from this determination is compatible with the mechanism of lithium cation transport by the diffusion of salt molecules. Elasticity modulus measurements show that the salt aggregates are essentially located within the crosslinks at low concentration, but also in the PEO chains for salt concentrations higher than 1 mol/l.

Electrical conductivity studies on silica phases and the effects of phase transformation

2019 ◽  
Vol 104 (12) ◽  
pp. 1800-1805
Author(s):  
George M. Amulele ◽  
Anthony W. Lanati ◽  
Simon M. Clark
Keyword(s):  
Electrical Conductivity ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Hydrogen Charge ◽  
Charge Compensation ◽  
Composition Analysis ◽  
Conductivity Measurements ◽  
Pressure System ◽  
Electrical Conductivities ◽  
Silica Phases

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.

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