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authors |
Ravkina, O; Yaremchenko, A; Feldhoff, A |
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nationality |
International |
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journal |
JOURNAL OF MEMBRANE SCIENCE |
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author keywords |
Ba0.5Sr0.5Co0.8Fe0.2O3-delta; Phase decomposition; High oxygen pressure; Oxygen nonstoichiometry; Electron microscopy |
|
keywords |
OXIDE FUEL-CELLS; SITU NEUTRON-DIFFRACTION; BA0.5SR0.5CO0.8FE0.2O3-DELTA PEROVSKITE; STRUCTURAL STABILITY; ELECTRON-MICROSCOPY; MEMBRANES; PERMEATION; SRCO0.8FE0.2O3-DELTA; NONSTOICHIOMETRY; PERFORMANCE |
|
abstract |
The influence of elevated oxygen pressure (from 1 to 50 bar) on phase separation in Ba0.5Sr0.5Co0.8Fe0.2O3-delta(BSCF) cubic perovskite was investigated in the range of 300to 1300 K. X-ray diffraction and thermogravimetric analysis revealed two separation processes occurring in the high temperature (HT), 1043 K, and low temperature (LT), 713 K, ranges. Increasing oxygen pressure shifts slightly the LT phase separation to lower temperature, but has a rather minor effect on the volume fraction growth of the secondary phase. Phase transformation in the HT range is a slow process and the degree of decomposition is strongly influenced by the cooling rate from higher temperatures. On the contrary, the LT separation is relatively fast and is essentially independent of the cooling rate. The BSCF ceramics thermally treated at p(O-2)=50 bar was analyzed by different electron microscopy techniques. The structures of separation products were identified as trigonal Ba3Co10O17-like lamellae and 2H-hex-agonal Ba-0.5 (+/-) Sr-x(0.5) (+/-) xCoO3-delta perovskite, respectively. (C) 2016 Elsevier B.V. All rights reserved. |
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publisher |
ELSEVIER SCIENCE BV |
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issn |
0376-7388 |
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year published |
2016 |
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volume |
520 |
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beginning page |
76 |
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ending page |
88 |
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digital object identifier (doi) |
10.1016/j.memsci.2016.07.047 |
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web of science category |
Engineering, Chemical; Polymer Science |
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subject category |
Engineering; Polymer Science |
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unique article identifier |
WOS:000384785000009
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