Details
| Original language | English |
|---|---|
| Pages (from-to) | 375-382 |
| Number of pages | 8 |
| Journal | Journal of membrane science |
| Volume | 322 |
| Issue number | 2 |
| Early online date | 8 Jun 2008 |
| Publication status | Published - 15 Sept 2008 |
Abstract
The effect of grain size distribution in perovskite-type (Ba0.5Sr0.5)(Fe0.8Zn0.2)O3-δ (BSFZ) ceramics on their oxygen permeation behaviour has been investigated by variation of calcination temperature in powder production and sintering time for the ceramics. The membranes were examined via scanning electron microscopy (SEM), transmission electron microscopy (TEM) and oxygen permeation experiments. We found that the dwell time during sintering has an important influence on the microstructure of the ceramic. The longer the dwell time, the further proceeds the grain coarsening, which affects the oxygen permeation in a positive way and leads to an enhanced permeation. Supplementary, decreasing calcination temperature in perovskite powder synthesis delivers fine powders with grain sizes less than one micrometer and thus smaller grains in the ceramic. Unfortunately, the grain size distribution in sintered membranes is not constant through membrane cross-sections since grains in the bulk are smaller compared to those at the surface which is not favorable for the oxygen permeation of the ceramics. The activation energy was determined to be in the range of 51-53 kJ/mol and its variation does not exhibit a dependence of grain size changes. High-resolution transmission electron microscopy proved that grain boundaries are atomically thin without any interfacial phases. We come to the conclusion that the transport rate of the oxygen permeation is limited predominantly by bulk diffusion and due to the fact that grain boundaries in BSFZ act as barriers for bulk diffusion, this material is a high mobility material.
Keywords
- BSFZ, Grain size distribution, Microstructure, Oxygen permeation, Perovskite membrane
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Materials Science(all)
- General Materials Science
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemical Engineering(all)
- Filtration and Separation
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In: Journal of membrane science, Vol. 322, No. 2, 15.09.2008, p. 375-382.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of grain size on the oxygen permeation performance of perovskite-type (Ba0.5Sr0.5)(Fe0.8Zn0.2)O3-δ membranes
AU - Martynczuk, Julia
AU - Arnold, Mirko
AU - Feldhoff, Armin
N1 - Funding Information: The authors greatly acknowledge financial support by DFG grant number FE 928/1-2 and fruitful discussions with Prof. Jürgen Caro.
PY - 2008/9/15
Y1 - 2008/9/15
N2 - The effect of grain size distribution in perovskite-type (Ba0.5Sr0.5)(Fe0.8Zn0.2)O3-δ (BSFZ) ceramics on their oxygen permeation behaviour has been investigated by variation of calcination temperature in powder production and sintering time for the ceramics. The membranes were examined via scanning electron microscopy (SEM), transmission electron microscopy (TEM) and oxygen permeation experiments. We found that the dwell time during sintering has an important influence on the microstructure of the ceramic. The longer the dwell time, the further proceeds the grain coarsening, which affects the oxygen permeation in a positive way and leads to an enhanced permeation. Supplementary, decreasing calcination temperature in perovskite powder synthesis delivers fine powders with grain sizes less than one micrometer and thus smaller grains in the ceramic. Unfortunately, the grain size distribution in sintered membranes is not constant through membrane cross-sections since grains in the bulk are smaller compared to those at the surface which is not favorable for the oxygen permeation of the ceramics. The activation energy was determined to be in the range of 51-53 kJ/mol and its variation does not exhibit a dependence of grain size changes. High-resolution transmission electron microscopy proved that grain boundaries are atomically thin without any interfacial phases. We come to the conclusion that the transport rate of the oxygen permeation is limited predominantly by bulk diffusion and due to the fact that grain boundaries in BSFZ act as barriers for bulk diffusion, this material is a high mobility material.
AB - The effect of grain size distribution in perovskite-type (Ba0.5Sr0.5)(Fe0.8Zn0.2)O3-δ (BSFZ) ceramics on their oxygen permeation behaviour has been investigated by variation of calcination temperature in powder production and sintering time for the ceramics. The membranes were examined via scanning electron microscopy (SEM), transmission electron microscopy (TEM) and oxygen permeation experiments. We found that the dwell time during sintering has an important influence on the microstructure of the ceramic. The longer the dwell time, the further proceeds the grain coarsening, which affects the oxygen permeation in a positive way and leads to an enhanced permeation. Supplementary, decreasing calcination temperature in perovskite powder synthesis delivers fine powders with grain sizes less than one micrometer and thus smaller grains in the ceramic. Unfortunately, the grain size distribution in sintered membranes is not constant through membrane cross-sections since grains in the bulk are smaller compared to those at the surface which is not favorable for the oxygen permeation of the ceramics. The activation energy was determined to be in the range of 51-53 kJ/mol and its variation does not exhibit a dependence of grain size changes. High-resolution transmission electron microscopy proved that grain boundaries are atomically thin without any interfacial phases. We come to the conclusion that the transport rate of the oxygen permeation is limited predominantly by bulk diffusion and due to the fact that grain boundaries in BSFZ act as barriers for bulk diffusion, this material is a high mobility material.
KW - BSFZ
KW - Grain size distribution
KW - Microstructure
KW - Oxygen permeation
KW - Perovskite membrane
UR - http://www.scopus.com/inward/record.url?scp=48149097362&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2008.05.064
DO - 10.1016/j.memsci.2008.05.064
M3 - Article
AN - SCOPUS:48149097362
VL - 322
SP - 375
EP - 382
JO - Journal of membrane science
JF - Journal of membrane science
SN - 0376-7388
IS - 2
ER -