Details
| Original language | English |
|---|---|
| Pages (from-to) | 1586-1594 |
| Number of pages | 9 |
| Journal | Chemistry of Materials |
| Volume | 21 |
| Issue number | 8 |
| Early online date | 26 Mar 2009 |
| Publication status | Published - 28 Apr 2009 |
Abstract
Previously unreleased compositions of (Ba0.5Sr 0.5)(Fe1-xAlx)O3-δ perovskites in the range of 0≤x≤ 0.2 were synthesized and studied with respect to electronic and crystallographic structure, as well as oxygen permeation. The perovskite phase in all synthesized oxides was found to be cubic, without any impurities for aluminum fractions in the range x = 0.01-0.09. Electron energy-loss spectroscopy (EELS) revealed a significant amount of covalency by Fe-3d-O-2p hybridization and a mixed Fe3+ /Fe4+ valence state of iron for all synthesized perovskites, which was quantified by Mössbauer spectroscopy. Trivalent aluminum replaces a higher fraction of Fe4+ than of Fe3+ while both iron species are in high-spin state. The Mössbauer quadrupole splittings indicate a greater disorder around iron with increasing aluminum content and, together with the EELS result of an abatement of covalent character in the bonding of iron and oxygen, the observed lattice expansion can be understood. In situ XRD and TG/DTA measurements revealed high temperature stability of the materials up to 1350 C°. The oxygen permeation increases with rising aluminum content from 0 to 0.1, and the (Ba0.5 Sr0.5)(Fe0.9Al 0.1)O3-δ membranes show a very high oxygen permeation (1.19 mL cm-2 min-1 at 950 C°) compared to known perovskite membranes. Even among the previously published iron and aluminum containing membranes, they exhibit the highest oxygen permeation.
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Chemical Engineering(all)
- General Chemical Engineering
- Materials Science(all)
- Materials Chemistry
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In: Chemistry of Materials, Vol. 21, No. 8, 28.04.2009, p. 1586-1594.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Aluminum-Doped perovskites as high-performance oxygen permeation materials
AU - Martynczuk, Julia
AU - Liang, Fangyi
AU - Arnold, Mirko
AU - Šepelák, Vladimir
AU - Feldhoff, Armin
PY - 2009/4/28
Y1 - 2009/4/28
N2 - Previously unreleased compositions of (Ba0.5Sr 0.5)(Fe1-xAlx)O3-δ perovskites in the range of 0≤x≤ 0.2 were synthesized and studied with respect to electronic and crystallographic structure, as well as oxygen permeation. The perovskite phase in all synthesized oxides was found to be cubic, without any impurities for aluminum fractions in the range x = 0.01-0.09. Electron energy-loss spectroscopy (EELS) revealed a significant amount of covalency by Fe-3d-O-2p hybridization and a mixed Fe3+ /Fe4+ valence state of iron for all synthesized perovskites, which was quantified by Mössbauer spectroscopy. Trivalent aluminum replaces a higher fraction of Fe4+ than of Fe3+ while both iron species are in high-spin state. The Mössbauer quadrupole splittings indicate a greater disorder around iron with increasing aluminum content and, together with the EELS result of an abatement of covalent character in the bonding of iron and oxygen, the observed lattice expansion can be understood. In situ XRD and TG/DTA measurements revealed high temperature stability of the materials up to 1350 C°. The oxygen permeation increases with rising aluminum content from 0 to 0.1, and the (Ba0.5 Sr0.5)(Fe0.9Al 0.1)O3-δ membranes show a very high oxygen permeation (1.19 mL cm-2 min-1 at 950 C°) compared to known perovskite membranes. Even among the previously published iron and aluminum containing membranes, they exhibit the highest oxygen permeation.
AB - Previously unreleased compositions of (Ba0.5Sr 0.5)(Fe1-xAlx)O3-δ perovskites in the range of 0≤x≤ 0.2 were synthesized and studied with respect to electronic and crystallographic structure, as well as oxygen permeation. The perovskite phase in all synthesized oxides was found to be cubic, without any impurities for aluminum fractions in the range x = 0.01-0.09. Electron energy-loss spectroscopy (EELS) revealed a significant amount of covalency by Fe-3d-O-2p hybridization and a mixed Fe3+ /Fe4+ valence state of iron for all synthesized perovskites, which was quantified by Mössbauer spectroscopy. Trivalent aluminum replaces a higher fraction of Fe4+ than of Fe3+ while both iron species are in high-spin state. The Mössbauer quadrupole splittings indicate a greater disorder around iron with increasing aluminum content and, together with the EELS result of an abatement of covalent character in the bonding of iron and oxygen, the observed lattice expansion can be understood. In situ XRD and TG/DTA measurements revealed high temperature stability of the materials up to 1350 C°. The oxygen permeation increases with rising aluminum content from 0 to 0.1, and the (Ba0.5 Sr0.5)(Fe0.9Al 0.1)O3-δ membranes show a very high oxygen permeation (1.19 mL cm-2 min-1 at 950 C°) compared to known perovskite membranes. Even among the previously published iron and aluminum containing membranes, they exhibit the highest oxygen permeation.
UR - http://www.scopus.com/inward/record.url?scp=66149099697&partnerID=8YFLogxK
U2 - 10.1021/cm803217t
DO - 10.1021/cm803217t
M3 - Article
AN - SCOPUS:66149099697
VL - 21
SP - 1586
EP - 1594
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 8
ER -