Processing and Electrochemical Properties of Mixed Conducting Lat-xAxCo1-yFeyO3-δ (A=Sr, Ca)

1994 ◽  
Vol 369 ◽  
Author(s):  
W. J. Weber ◽  
J. W. Stevenson ◽  
T. R. Armstrong ◽  
L. R. Pederson ◽  
J. J. Kingsley
Keyword(s):  
Perovskite Structure ◽  
Applied Field ◽  
Synthesis Method ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion ◽  
Electrical Conductivities ◽  
Permeation Studies ◽  
Thermogravimetric Studies ◽  
Increasing Temperature ◽  
Significant Flux

AbstractPowder compositions in the series Lat-xAxCo1-yFeyO3-δ (A=Sr, Ca) have been prepared by a combustion synthesis method. Sintering of pressed powders produced high-density test specimens with the perovskite structure. The specimens exhibited high electrical conductivities with appreciable oxygen-ion conductivity that increased with Co content for the compositions studied. Oxygen permeation studies showed a significant flux of oxygen that increased with temperature for specimens in a P(O2) gradient with no applied field. Thermogravimetric studies of the Lat-xCo0.2Fe0.8O3-δ system indicated a reversible mass loss with increasing temperature that increased with Sr content.

scholarly journals Mechanochemical Synthesis and Nitrogenation of the Nd1.1Fe10CoTi Alloy for Permanent Magnet

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3854
Author(s):  
Hugo Martínez Sánchez ◽  
George Hadjipanayis ◽  
Germán Antonio Pérez Alcázar ◽  
Ligia Edith Zamora Alfonso ◽  
Juan Sebastián Trujillo Hernández
Keyword(s):  
Mechanochemical Synthesis ◽  
Applied Field ◽  
Volume Fraction ◽  
Synthesis Method ◽  
High Energy ◽  
Direction Parallel ◽  
Best Value ◽  
Heat Treated ◽  
Bcc Phase ◽  
First Time

In this work, the mechanochemical synthesis method was used for the first time to produce powders of the nanocrystalline Nd1.1Fe10CoTi compound from Nd2O3, Fe2O3, Co and TiO2. High-energy-milled powders were heat treated at 1000 °C for 10 min to obtain the ThMn12-type structure. Volume fraction of the 1:12 phase was found to be as high as 95.7% with 4.3% of a bcc phase also present. The nitrogenation process of the sample was carried out at 350 °C during 3, 6, 9 and 12 h using a static pressure of 80 kPa of N2. The magnetic properties Mr, µ0Hc, and (BH)max were enhanced after nitrogenation, despite finding some residual nitrogen-free 1:12 phase. The magnetic values of a nitrogenated sample after 3 h were Mr = 75 Am2 kg–1, µ0Hc = 0.500 T and (BH)max = 58 kJ·m–3. Samples were aligned under an applied field of 2 T after washing and were measured in a direction parallel to the applied field. The best value of (BH)max~114 kJ·m–3 was obtained for 3 h and the highest µ0Hc = 0.518 T for 6 h nitrogenation. SEM characterization revealed that the particles have a mean particle size around 360 nm and a rounded shape.

Oxygen-ion Conductivity of Re Tungstates Ln14W4O33 (Ln = Nd, Sm, Gd)

2021 ◽  
Author(s):  
Anna Shlyakhtina ◽  
Nikolay Lyskov ◽  
Sergei Cheryak ◽  
Igor Kolbanev ◽  
Anna Kasyanova ◽  
...  
Keyword(s):  
Ion Conductivity ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion

Doped Ceria Based Solid Oxide Fuel Cell Electrolytes and their Sintering Aspects: An Overview

2016 ◽  
Vol 835 ◽  
pp. 199-236 ◽  
Author(s):  
Pradyot Datta
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Operating Temperature ◽  
Solid Oxide ◽  
Ion Conductivity ◽  
Doped Ceria ◽  
Oxide Fuel ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion

Depletion of fossil fuel at an alarming rate is a major concern of humankind. Consequently, researchers all over the world are putting a concerted effort for finding alternative and renewable energy. Solid oxide fuel cell (SOFC) is one such system. SOFCs are electrochemical devices that have several advantages over conventional power generation systems like high efficiency of power generation, low emission of green house gases and the fuel flexibility. The major research focus of recent times is to reduce the operating temperature of SOFC in the range of 500 to 700 °C so as to render it commercially viable. This reduction in temperature is largely dependent on finding an electrolyte material with adequate oxygen ion conductivity at the intended operating temperature. One much material is Gadolinia doped Ceria (CGO) that shows very good oxygen ion conductivity at the intended operation temperature. The aim of this overview is to highlight the contribution that materials chemistry has made to the development of CGO as an electrolyte.

Mixed Ionic-Electronic Conduction in Pyrochlore Oxides

1990 ◽  
Vol 210 ◽  
Author(s):  
M. Spears ◽  
S. Kramer ◽  
P.K. Moon ◽  
H.L. Tuller
Keyword(s):  
Electronic Transport ◽  
Ionic Conduction ◽  
Structural Disorder ◽  
Electronic Conduction ◽  
Transport Parameters ◽  
Oxygen Ion Conductivity ◽  
Chemical Models ◽  
Oxygen Ion ◽  
Electrochemical Devices ◽  
Low X

AbstractThe transport properties of the pyrochlore solid solution Gd2(ZrxTil-x)2O7 are investigated to clarify the relationships between composition, structural disorder and ionic and electronic transport. The oxygen ion conductivity has been found to increase sharply with increasing Zr content, x, due to enhanced structural disorder, leading to intrinsic ionic conduction at large values ofx. In contrast, the n—type conductivity predominant at low x, decreases sharply above x=0.2. Defect chemical models are presented to account for the simultaneous contributions of both intrinsic and dopant induced disorder. These models are applied to the σ(T, PO2, dopant) data to extract key thermodynamic and transport parameters. The significance of these parameters and the potential application of these materials in electrochemical devices are discussed.

scholarly journals Dense lanthanum silicate oxyapatite ceramics obtained by uniaxial pressing and slip casting

2018 ◽  
Vol 50 (4) ◽  
pp. 433-443
Author(s):  
Ramiro Toja ◽  
Nicolás Rendtorffa ◽  
Esteban Agliettia ◽  
Tetsuo Uchikoshi ◽  
Yoshio Sakka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Growth Process ◽  
Slip Casting ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion ◽  
Slip Cast ◽  
Lanthanum Silicate

Lanthanum silicate oxyapatite (LSO) is a promising ion conductive ceramic material, which has higher oxygen ion conductivity at intermediate temperatures (600-800?C) compared to yttria-stabilized zirconia. Its mechanical properties, though important for any of its applications, have been scarcely reported. In this study, we compare apparent densification, open porosity and Vickers hardness of samples conformed by uniaxial pressing and slip casting and fired up to 1600?C. Colloidal processing was optimized for slip casting in order to get high green densities. At sintering temperatures higher than 1400?C, both processing routes yielded comparable densities, although uniaxially pressed samples show slightly better mechanical properties, evidencing that slip cast ones already underwent a grain growth process.

Oxygen ion conductivity of hexagonal La2W1.25O6.75

1999 ◽  
Vol 38 (4) ◽  
pp. 300-304 ◽  
Author(s):  
A.V Kovalevsky ◽  
V.V Kharton ◽  
E.N Naumovich
Keyword(s):  
Ion Conductivity ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion

scholarly journals Anisotropic Proton and Oxygen Ion Conductivity in Epitaxial Ba2In2O5 Thin Films

2017 ◽  
Vol 121 (40) ◽  
pp. 21797-21805 ◽  
Author(s):  
Aline Fluri ◽  
Elisa Gilardi ◽  
Maths Karlsson ◽  
Vladimir Roddatis ◽  
Marco Bettinelli ◽  
...  
Keyword(s):  
Thin Films ◽  
Ion Conductivity ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion

Enhanced Oxygen Ion Conductivity in Composite Film Electrolytes with Aligned Nanowires

2018 ◽  
Vol 5 (13) ◽  
pp. 1800098 ◽  
Author(s):  
Mengfei Zhang ◽  
Tianjun Li ◽  
Zheng Li ◽  
Yan Xing ◽  
Xiaohui Zhao ◽  
...  
Keyword(s):  
Composite Film ◽  
Ion Conductivity ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion

scholarly journals Discovery of zirconium dioxides for the design of better oxygen-ion conductors using efficient algorithms beyond data mining

RSC Advances ◽  
2018 ◽  
Vol 8 (45) ◽  
pp. 25534-25545 ◽  
Author(s):  
Joohwi Lee ◽  
Nobuko Ohba ◽  
Ryoji Asahi
Keyword(s):  
Data Mining ◽  
Regression Analysis ◽  
Evolutionary Algorithms ◽  
Crystal Structures ◽  
First Principles ◽  
Efficient Algorithms ◽  
First Principles Calculations ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion ◽  
Oxygen Ion Conductors

Search for crystal structures of ZrO2 with higher oxygen-ion conductivity by evolutionary algorithms, first-principles calculations, and regression analysis.

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