Structural Characterization and Ionic Conductivity of Metastable Gd2(Ti0.65Zr0.35)2O7 Powders Prepared by Mechanical Milling

2006 ◽  
Vol 972 ◽  
Author(s):  
Antonio F. Fuentes ◽  
Karla J. Moreno ◽  
Jacobo Santamaria ◽  
Carlos Leon ◽  
Ulises Amador
Keyword(s):  
Ionic Conductivity ◽  
Mechanical Milling ◽  
Sintering Temperature ◽  
Ion Dynamics ◽  
Conductivity Relaxation ◽  
Electrical Conductivity Relaxation ◽  
Ion Interactions ◽  
Oxygen Ion ◽  
Fluorite Type ◽  
Powder Phase

AbstractWe analyze in this work the influence of ordering on the oxygen ion dynamics in the ionic conductor Gd2(Ti0.65Zr0.35)2O7, prepared by mechanical milling. As-prepared powder phase presents a metastable anion deficient fluorite-type of structure below 800°C becoming a disordered pyrochlore above this temperature. Such phase transformation implies a significant increase in the ionic conductivity of this material as a result of a systematic decrease in the activation energy for the dc conductivity, from 1.23 to 0.78 eV. Electrical conductivity relaxation is well described by the Kohlrausch-Williams-Watts (KWW) stretched exponential function with the fractional exponent n decreasing systematically with increasing sintering temperature (increasing ordering) as a result of decreasing ion-ion interactions in better ordered samples.

A Study of the Oxygen Transport Kinetics in SrFeO3-x

2002 ◽  
Vol 756 ◽  
Author(s):  
Jiho Yoo ◽  
Allan J. Jacobson
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Transport ◽  
Diffusion Coefficients ◽  
Abrupt Change ◽  
Vacancy Diffusion ◽  
Conductivity Relaxation ◽  
Surface Exchange ◽  
Electrical Conductivity Relaxation ◽  
Oxygen Ion ◽  
Thermodynamic Factors

ABSTRACTExperimental results from electrical conductivity relaxation (ECR) measurements on SrFeO3-x are described. Values of Dchem and kchem were obtained by monitoring the variation of the time dependence of the electrical conductivity after an abrupt change in the oxygen partial pressure. Values for the oxygen ion and vacancy diffusion coefficients were calculated from the measured thermodynamic factors and compared with those of other compositions in the series La1-xSrxFeO3-x. The surface exchange coefficients, kchem and kex were also determined.

scholarly journals Effects of (Li-Na)2CO3 on The Electrical Properties of Calcia-Stabilized Zirconia/Carbonate Composite Electrolytes

2022 ◽  
Vol 334 ◽  
pp. 04014
Author(s):  
Aiman Iqbal ◽  
Pramujo Widiatmoko ◽  
Hary Devianto
Keyword(s):  
Fuel Cell ◽  
Ionic Conductivity ◽  
Sintering Temperature ◽  
Low Cost ◽  
Fluorite Structure ◽  
Carbonate Content ◽  
Stabilized Zirconia ◽  
Oxygen Conductivity ◽  
Fuel Cell Performance ◽  
Oxygen Ion

Calcia-Stabilized Zirconia (CSZ) is potential as low-cost electrolytes material for Solid oxide fuel cell (SOFC). It is fluorite structure widely known as oxygen ion conductors. Addition of carbonate salt into fluorite-based electrolyte is common to overcome low conductivity of CSZ as well as to decrease sintering temperature. Increase of ionic conductivity in the SOFC electrolyte is also influenced by presence of protons (H+), so it is called mixed-ion electrolytes. In this study, the effect of sintering temperature and carbonate content prepared from mixture of Li2CO3 and Na2CO3 on the relative density, ionic conductivity and microstructure of electrolyte and fuel cell performance was investigated. The sintered CSZ/carbonate samples were examined physically and electrochemically by using SEM, TEM, XRD, and EIS. The unique detail of nanostructure for CSZ/carbonate was investigated by TEM. The XRD is to observed peak associating with CSZ, Li2CO3, and Na2CO3, as well as its crystallinity. Moreover, the electrolyte resistance was measured by EIS so that the proton conductivity and oxygen conductivity of CSZ/carbonate can be calculated. The improvement of low-cost electrolyte material such as CSZ can be realized by providing protons pathway.

Electrical conductivity relaxation of Sr2Fe1.5Mo0.5O6−δ–Sm0.2Ce0.8O1.9dual-phase composites

2014 ◽  
Vol 2 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Yunlong Wang ◽  
Bobing Hu ◽  
Zhuoying Zhu ◽  
Henny J. M. Bouwmeester ◽  
Changrong Xia
Keyword(s):  
Electrical Conductivity ◽  
Conductivity Relaxation ◽  
Electrical Conductivity Relaxation

scholarly journals Dielectric and impedance analysis of Li0.5La0.5Ti1-xZrxO3(x = 0.05 and 0.1) ceramics as improved electrolyte material for lithium-ion batteries

2016 ◽  
Vol 34 (3) ◽  
pp. 605-616 ◽  
Author(s):  
K. Vijaya Babu ◽  
V. Veeraiah
Keyword(s):  
Ionic Conductivity ◽  
Lithium Ion Batteries ◽  
Electric Modulus ◽  
Lithium Ion ◽  
Impedance Analysis ◽  
Solid State Reaction Method ◽  
High Ionic Conductivity ◽  
Conductivity Relaxation ◽  
Reaction Method ◽  
X Ray

AbstractThe most attractive property of Li0.5La0.5TiO3 (LLTO) electrolytes is their high ionic conductivity. Studies have shown that LLTO is capable of existing in a state with an ionic conductivity of 10-3 S/cm, which is comparable to liquid electrolytes. In addition to the high ionic conductivity of the material, LLTO is electrochemically stable and able to withstand hundreds of cycles. So, the studies of the solid electrolyte material are very important for the development of lithium-ion batteries. In the present paper, Li0.5La0.5Ti1-xZrxO3 (x = 0.05 and 0.1) have been prepared by a solid-state reaction method at 1300 °C for 6 hours to improve electrolyte materials for lithium-ion batteries. The phase identified by X-ray diffractometry and crystal structure corresponds to pm3m (2 2 1) space group (Z = 1). The frequency and temperature dependence of impedance, dielectric permittivity, dielectric loss and electric modulus of the Li0.5La0.5Ti1-xZrxO3 (x = 0.05 and 0.1) have been investigated. The dielectric and impedance properties have been studied over a range of frequency (42 Hz to 5 MHz) and temperatures (30 °C to 100 °C). The frequency dependent plot of modulus shows that the conductivity relaxation is of non-Debye type.

Sintering behavior and ionic conductivity of Li1.5Al0.5Ti1.5(PO4)3 synthesized with different precursors

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bambar Davaasuren ◽  
Qianli Ma ◽  
Alexandra von der Heiden ◽  
Frank Tietz
Keyword(s):  
Grain Size ◽  
Solid State ◽  
Ionic Conductivity ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Homogeneous Microstructure ◽  
Micro Cracks ◽  
Primary Particles ◽  
Total Ionic Conductivity

Abstract Li1.5Al0.5Ti1.5(PO4)3 (LATP) powders were prepared from different NO x -free precursors using an aqueous-based solution-assisted solid-state reaction (SA-SSR). The sintering behavior, phase formation, microstructure and ionic conductivity of the powders were explored as a function of sintering temperature. The powders showed a relatively narrow temperature windows in which shrinkage occurred. Relative densities of 95% were reached upon heating between 900 and 960 °C. Depending on the morphological features of the primary particles, either homogeneous and intact microstructures with fine grains of about <2 µm in size or a broad grain size distribution, micro-cracks and grain cleavages were obtained, indicating the instability of the microstructure. Consequently, the ceramics with a homogeneous microstructure possessed a maximum total ionic conductivity of 0.67 mS cm−1, whereas other ceramics reached only 0.58 mS cm−1 and 0.21 mS cm−1.

Enhanced Room-Temperature Ionic Conductivity of NaCB11H12 via High-Energy Mechanical Milling

2021 ◽  
Author(s):  
Fabrizio Murgia ◽  
Matteo Brighi ◽  
Laura Piveteau ◽  
Claudia E. Avalos ◽  
Valerio Gulino ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Mechanical Milling ◽  
Room Temperature ◽  
High Energy
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