Details
| Original language | English |
|---|---|
| Pages (from-to) | 8-15 |
| Number of pages | 8 |
| Journal | Solid State Ionics |
| Volume | 222-223 |
| Early online date | 20 Jul 2012 |
| Publication status | Published - 20 Aug 2012 |
Abstract
The Ruddlesden-Popper (RP) phases La 2Ni 1 - xFe xO 4 + δ (x = 0.02, 0.1) and La 4Ni 3 - xFe xO 10 - δ (x = 0.3, 0.9) were successfully synthesized via the sol-gel route. Even though X-ray diffraction did not show any secondary phases for La 2Ni 0.9Fe 0.1O 4 + δ, approximately 5-10% of the higher order RP phase La 4Ni 2.1Fe 0.9O 10 - δ were detected in backscattered electron contrast imaging, whereas La 2Ni 0.98Fe 0.02O 4 + δ exhibits no foreign phases. This was also confirmed by transmission electron microscopy (TEM). Furthermore, the oxygen permeation performance and electrical conductivity of La 2Ni 1 -xFe xO 4 + δ were found to decrease slightly with increasing iron content. The Mössbauer spectra of La 2Ni 1 -xFe xO 4 + δ (x = 0.02, 0.1) are dominated by a quadrupole-split doublet. With increasing temperature, however, a minority iron species is detected. The dominating doublet reveals an unusual high-temperature behavior of quadrupolar interactions, which was observed by in-situ Mössbauer measurements at high temperatures and different oxygen partial pressures. This is most likely related to ordering phenomena of oxygen.
Keywords
- Electrical conductivity, In-situ Mössbauer spectroscopy, Oxygen permeation, Ruddlesden-Popper phases, Transmission electron microscopy
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Solid State Ionics, Vol. 222-223, 20.08.2012, p. 8-15.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - In-situ Mössbauer studies of 57Fe-doped Ruddlesden-Popper type lanthanum nickel oxides
AU - Klande, Tobias
AU - Cusenza, Salvatore
AU - Gaczyński, Piotr
AU - Becker, Klaus Dieter
AU - Dörrer, Lars
AU - Borchardt, Günter
AU - Feldhoff, Armin
N1 - Funding Information: Financial support from the State of Lower Saxony in the frame of NTH bottom-up project No. 21-71023-25-7/09 is gratefully acknowledged. We like to thank Hannes Töpfer and Mladen Zec (TU Ilmenau) for the helpful discussions and for the FEM calculations of the four-point geometry of the conductivity measurements.
PY - 2012/8/20
Y1 - 2012/8/20
N2 - The Ruddlesden-Popper (RP) phases La 2Ni 1 - xFe xO 4 + δ (x = 0.02, 0.1) and La 4Ni 3 - xFe xO 10 - δ (x = 0.3, 0.9) were successfully synthesized via the sol-gel route. Even though X-ray diffraction did not show any secondary phases for La 2Ni 0.9Fe 0.1O 4 + δ, approximately 5-10% of the higher order RP phase La 4Ni 2.1Fe 0.9O 10 - δ were detected in backscattered electron contrast imaging, whereas La 2Ni 0.98Fe 0.02O 4 + δ exhibits no foreign phases. This was also confirmed by transmission electron microscopy (TEM). Furthermore, the oxygen permeation performance and electrical conductivity of La 2Ni 1 -xFe xO 4 + δ were found to decrease slightly with increasing iron content. The Mössbauer spectra of La 2Ni 1 -xFe xO 4 + δ (x = 0.02, 0.1) are dominated by a quadrupole-split doublet. With increasing temperature, however, a minority iron species is detected. The dominating doublet reveals an unusual high-temperature behavior of quadrupolar interactions, which was observed by in-situ Mössbauer measurements at high temperatures and different oxygen partial pressures. This is most likely related to ordering phenomena of oxygen.
AB - The Ruddlesden-Popper (RP) phases La 2Ni 1 - xFe xO 4 + δ (x = 0.02, 0.1) and La 4Ni 3 - xFe xO 10 - δ (x = 0.3, 0.9) were successfully synthesized via the sol-gel route. Even though X-ray diffraction did not show any secondary phases for La 2Ni 0.9Fe 0.1O 4 + δ, approximately 5-10% of the higher order RP phase La 4Ni 2.1Fe 0.9O 10 - δ were detected in backscattered electron contrast imaging, whereas La 2Ni 0.98Fe 0.02O 4 + δ exhibits no foreign phases. This was also confirmed by transmission electron microscopy (TEM). Furthermore, the oxygen permeation performance and electrical conductivity of La 2Ni 1 -xFe xO 4 + δ were found to decrease slightly with increasing iron content. The Mössbauer spectra of La 2Ni 1 -xFe xO 4 + δ (x = 0.02, 0.1) are dominated by a quadrupole-split doublet. With increasing temperature, however, a minority iron species is detected. The dominating doublet reveals an unusual high-temperature behavior of quadrupolar interactions, which was observed by in-situ Mössbauer measurements at high temperatures and different oxygen partial pressures. This is most likely related to ordering phenomena of oxygen.
KW - Electrical conductivity
KW - In-situ Mössbauer spectroscopy
KW - Oxygen permeation
KW - Ruddlesden-Popper phases
KW - Transmission electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=84864063409&partnerID=8YFLogxK
U2 - 10.1016/j.ssi.2012.06.019
DO - 10.1016/j.ssi.2012.06.019
M3 - Article
AN - SCOPUS:84864063409
VL - 222-223
SP - 8
EP - 15
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
ER -