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Effect of Mn valence on crystal structure of La–Mn–O perovskite oxides

Published online by Cambridge University Press:  03 March 2011

Takeshi Yao
Affiliation:
Graduate School of Engineering, Kyoto University, Yoshida-Honmach, Sakyo-ku, Kyoto-shi, Kyoto 606, Japan
Toyoji Ito
Affiliation:
Graduate School of Engineering, Kyoto University, Yoshida-Honmach, Sakyo-ku, Kyoto-shi, Kyoto 606, Japan
Tadashi Kokubo
Affiliation:
Graduate School of Engineering, Kyoto University, Yoshida-Honmach, Sakyo-ku, Kyoto-shi, Kyoto 606, Japan
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Abstract

La:Mn = 1:1 mixtures of lanthanum oxide and manganese carbonate were heat-treated under various oxygen partial pressures at 1400 °C or 1300 °C. The Mn valence of the samples was measured by a chemical analysis, and the crystal structures were refined by the powder x-ray diffraction and the Rietveld analysis. A novel orthorhombic perovskite phase, belonging to the space group Pbnm and containing - Mn2+ ions, was formed by heat-treatment under low oxygen partial pressures. The structure was very close to a cubic symmetry. It is supposed that the micro Jahn-Teller effects of Mn2+ ions were nearly canceled by one another.

Type
Communication
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1Fuel Cell System, edited by Blomen, L. J. M. J. and Mugerwa, M. N. (Plenum Press, New York, 1993), p. 470.CrossRefGoogle Scholar
2Kuo, J. H., Anderson, H. U., and Sparlin, D. M., J. Solid State Chem. 83, 52 (1989).CrossRefGoogle Scholar
3Kamata, K., Nakajima, T., Hayashi, T., and Nakamura, T., Mater. Res. Bull. XIII, 49 (1978).CrossRefGoogle Scholar
4Nakamura, T., Petzow, G., and Gauckler, L. J., Mater. Res. Bull. XIV, 649 (1979).CrossRefGoogle Scholar
5Kuo, J. H., Anderson, H. U., and Sparlin, D. M., J. Solid State Chem. 87, 55 (1990).CrossRefGoogle Scholar
6Takeda, Y., Nakai, S., Kojima, T., Kanno, R., Imanishi, N., Shen, G. Q., Yamamoto, O., Mori, M., Asakawa, C., and Abe, T., Mater. Res. Bull. XXVI, 153 (1991).CrossRefGoogle Scholar
7Yao, T., Report of Grant-in-Aid for Scientific Research (No. 02650560) from the Ministry of Education, Science and Culture, Japan (1992), p. 34.Google Scholar
8Oka, Y., Yao, T., and Yamamoto, N., J. Solid State Chem. 86, 116 (1990).CrossRefGoogle Scholar
9Oka, Y., Yao, T., and Yamamoto, N., J. Solid State Chem. 89, 372 (1990).CrossRefGoogle Scholar
10Yao, T., Oka, Y., and Yamamoto, N., Mater. Res. Bull. XXVII, 669 (1992).CrossRefGoogle Scholar
11Oka, Y., Yao, T., Yamamoto, N., Ueda, Y., and Hayashi, A., J. Solid State Chem. 105, 271 (1993).CrossRefGoogle Scholar
12Yao, T., Oka, Y., and Yamamoto, N., J. Solid State Chem. 112, 196 (1994).CrossRefGoogle Scholar
13Brist, C. and Lucco-Borlera, M., J. Inorg. Nucl. Chem. 27, 2129 (1965).CrossRefGoogle Scholar
14JCPDS No. 35-1353.Google Scholar