authors |
Kharton, VV; Kovalevsky, AV; Tsipis, EV; Viskup, AP; Naumovich, EN; Jurado, JR; Frade, JR |
nationality |
International |
journal |
JOURNAL OF SOLID STATE ELECTROCHEMISTRY |
author keywords |
perovskite; strontium ferrite; A-site deficiency; ionic conductivity; thermal expansion |
keywords |
OXIDE FUEL-CELLS; IONIC-CONDUCTIVITY; OXYGEN PERMEABILITY; THERMAL-EXPANSION; TRANSPORT; ELECTRODES; MEMBRANES; VACANCY; SYSTEM |
abstract |
Deficiency in the A sublattice of perovskite-type Sr1-yFe0.8Ti0.2O3-delta(y = 0-0.06) leads to suppression of oxygen-vacancy ordering and to increasing oxygen ionic conductivity, unit cell volume, thermal expansion, and stability in CO2-containing atmospheres. The total electrical conductivity, predominantly p-type electronic in air, decreases with increasing A-site deficiency at 300-700 K and is essentially independent of the cation vacancy concentration at higher temperatures. Oxygen ion transference numbers for Sr1-yFe0.8Ti0.2O3-delta in air, estimated from the faradaic efficiency and oxygen permeation data, vary in the range from 0.002 to 0.015 at 1073-1223 K, increasing with temperature. The maximum ionic conductivity was observed for Sr0.97Fe0.8Ti0.2O3-delta ceramics. In the system Sr0.97Fe1-xTixO3-delta (x=0.1-0.6), thermal expansion and electron-hole conductivity both decrease with x. Moderate additions of titanium (up to 20%) in Sr-0.97(Fe,Ti)O3-delta result in higher ionic conductivity and lower activation energy for ionic transport, owing to disordering in the oxygen sublattice; further doping decreases the ionic conduction. It was shown that time degradation of the oxygen permeability, characteristic of Sr(Fe,Ti)O3-delta membranes and resulting from partial ordering processes., can be reduced by cycling of the oxygen pressure at the membrane permeate side. Thermal expansion coefficients of Sr1-yTi1-xFexO3-delta (x=0.10-0.60, y=0-0.06) in air are in the range (11.7-16.5)x10(-6) K-1 at 350-750 K and(16.6-31.1)x10(-6) K-1 at 750-1050 K. |
publisher |
SPRINGER-VERLAG |
issn |
1432-8488 |
year published |
2002 |
volume |
7 |
issue |
1 |
beginning page |
30 |
ending page |
36 |
digital object identifier (doi) |
10.1007/s10008-002-0286-3 |
web of science category |
Electrochemistry |
subject category |
Electrochemistry |
unique article identifier |
WOS:000179980800007
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ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
2.646 |
5 year journal impact factor |
2.37 |
category normalized journal impact factor percentile |
50 |
dimensions (citation analysis):
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altmetrics (social interaction):
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