Relationship of crystal structure, lattice parameters and thermal expansion to nonstoichiometry in La{sub 1{minus}x}MnO{sub 3+d} and La{sub 1{minus}x}Sr{sub x}MnO{sub 3+d} determined by high-temperature X-ray diffraction under controlled oxygen partial pressures
- Tohoku Univ., Sendai (Japan). Research Inst. for Scientific Measurements
- Yokohama National Univ. (Japan). Inst. of Environmental Science and Technology
- Kyocera Corp., Kagoshima (Japan). Central Research Lab.
- Univ. of Tokyo (Japan)
To elucidate the phase change and volume variation of SOFC cathode materials, La{sub 1{minus}y}MnO{sub 3+d} (y = 0, 0.05) and La{sub 1{minus}x}Sr{sub x}MnO{sub 3+d}, with temperature and oxygen nonstoichiometry, high temperature X-ray diffraction analysis was made in the atmosphere of the controlled oxygen partial pressure. The structure above 800 C was found to be rhombohedral R{bar 3}C for the composition with x = 0 and 0.1, irrespective of the oxygen content. Both the lattice volume and thermal expansion coefficient increase with decreasing the oxygen content. For x{>=}0.3, the structure above 800 C was essentially cubic. The variation in the lattice parameter with P(O{sub 2}) at P(O{sub 2}) > 10{sup {minus}4} atm became smaller with the increase in Sr content, x, due to the smaller oxygen excess nonstoichiometry for the larger x in La{sub 1{minus}x}Sr{sub x}MnO{sub 3+d}.
- OSTI ID:
- 242498
- Report Number(s):
- CONF-950683-; ISBN 1-56677-095-5; TRN: IM9626%%326
- Resource Relation:
- Conference: 4. international symposium on solid oxide fuel cells, Yokohama (Japan), 18-23 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the fourth international symposium on solid oxide fuel cells (SOFC-IV). Proceedings Volume 95-1; Dokiya, M. [ed.] [National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (Japan)]; Yamamoto, O. [ed.] [Mie Univ., Tsu, Mie (Japan)]; Tagawa, H. [ed.] [Yokohama National Univ., Yokohama, Kanagawa (Japan)]; Singhal, S.C. [ed.] [Westinghouse Electric Corp., Pittsburgh, PA (United States)]; PB: 1188 p.
- Country of Publication:
- United States
- Language:
- English
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