This title appears in the Scientific Report :
2004
Please use the identifier:
http://dx.doi.org/10.1179/096797804X4213 in citations.
Statistical design of experiments for evaluation of Y-Zr-Ti oxides as anode materials in solid oxide fuel cells
Statistical design of experiments for evaluation of Y-Zr-Ti oxides as anode materials in solid oxide fuel cells
The synthetic vanadinites (Pb(x)Ca(10-x))(VO4)6F2delta, 1 < x < 9, adopt a P6(3)/m apatite structure with 9.7590 (1) < or = a < or = 10.1179 (1) A and 7.0434 (3) < or = c < or = 7.4021 (1) A. The partitioning of calcium and lead over the AI(4f) and AII(6h) positions is nonstoichiom...
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Personal Name(s): | Tietz, F. |
---|---|
Arul Raj, I. / Stöver, D. | |
Contributing Institute: |
Werkstoffsynthese und Herstellungsverfahren; IWV-1 |
Published in: | British ceramic transactions, 103 (2004) S. 202 - 210 |
Imprint: |
London
Maney Publishing
2004
|
Physical Description: |
202 - 210 |
PubMed ID: |
15017085 |
DOI: |
10.1179/096797804X4213 |
Document Type: |
Journal Article |
Research Program: |
Solid Oxide Fuel Cell Brennstoffzelle |
Series Title: |
British Ceramic Transactions
103 |
Subject (ZB): | |
Publikationsportal JuSER |
The synthetic vanadinites (Pb(x)Ca(10-x))(VO4)6F2delta, 1 < x < 9, adopt a P6(3)/m apatite structure with 9.7590 (1) < or = a < or = 10.1179 (1) A and 7.0434 (3) < or = c < or = 7.4021 (1) A. The partitioning of calcium and lead over the AI(4f) and AII(6h) positions is nonstoichiometric with lead preferentially entering the larger AII site. High-resolution electron microscopy showed that samples annealed for 10 h at 1073 K are in disequilibrium with calcium- and lead-rich microdomains co-existing at unit-cell scales. For (Pb5Ca5)(VO4)6F2delta, sintering in excess of 2 weeks is required for the metals to order macroscopically. As annealing progresses, c/a, the partitioning coefficient kPb(AI/AII) and the AIO6 metaprism twist angle (phi) adjust cooperatively to enlarge the apatite channel, and thereby accommodate higher lead content. These results demonstrate that phi is a sensitive measure of disequilibrium and a useful device for monitoring changes in apatite topology as a function of composition. |