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Valence variations in titanium-based perovskite oxides by high-pressure and high-temperature method

Published online by Cambridge University Press:  31 January 2011

Liping Li
Affiliation:
Department of Physics, Jilin University, Changchun 130023, People's Republic of China
Guangshe Li*
Affiliation:
Research Center of Supercritical Fluid Technology, Department of Chemical Engineering, Tohoku University, Sendai 980–8579, Japan
Jipeng Miao
Affiliation:
Department of Physics, Jilin University, Changchun 130023, People's Republic of China
Wenhui Su
Affiliation:
Department of Physics, Jilin University, Changchun 130023, People's Republic of China
Hiroshi Inomata
Affiliation:
Research Center of Supercritical Fluid Technology, Department of Chemical Engineering, Tohoku University, Sendai 980–8579, Japan
*
a)Address all correspondence to this author. e-mail: guangshe@scf.che.tohoku.ac.jp
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Abstract

Typical titanium-based perovskite oxides Eu1−xBaxTiO3 (x = 0.6−0.8), Eu1−xKxTiO3 (x = 0.2,0.32), and La0.7 (Na,K)0.3TiO3 were synthesized by high pressure and temperature using RE2O3 (RE = La,Eu), TiO2, alkaline, or alkaline earth carbonates as the starting materials. X-ray diffraction data analysis showed that there was a structural transformation in Eu1−xBaxTiO3 by varying Ba content [i.e., from cubic (x = 0.6,0.7) to tetragonal (x = 0.8)], and that samples Eu1−xKxTiO3 and La0.7(Na,K)0.3TiO3 crystallized in the cubic perovskite structure. 151Eu Mössbauer spectroscopy and electron paramagnetic resonance measurements revealed mixed valence of Eu2+/Eu3+ in samples Eu1−xBaxTiO3 and Eu1−xKxTiO3, while Ti ions were present in pure Ti4+ state. Cubic Eu1−xKxTiO3 was metastable, which decomposed into a mixture of perovskite and pyrochlore phases at high temperatures as accompanied by an oxidation process from Eu2+ to Eu3+. For samples La0.7 (Na,K)0.3TiO3, Ti3+ signals were clearly observed. The reduction mechanisms for Eu ions at A site and Ti ions at B site in the perovskite oxides are discussed in terms of the chemical nature of the framework ions and substitution ions under high pressure and temperature.

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Articles
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1.Jayaraman, A., in Handbook on the Physics and Chemistry of Rare Earth, edited by Gschneidner, K.A. Jr., and Eyring, L. (North-Holland Amsterdam, 1978), p. 707.Google Scholar
2.Zhou, J., Chinese J. High Pressure Phys. 6, 7 (1992).Google Scholar
3.Gemazeau, G., and Buffat, B., Mater. Res. Bull. 16, 1465 (1981).Google Scholar
4.Choy, H., Demazeau, G., Dance, J.M., Byeon, S.H., and Muller, K.A., J. Solid State Chem. 109, 289 (1994).CrossRefGoogle Scholar
5.Li, L., Wei, Q., Liu, H., Zheng, D., and Su, W., Z. Phys. B 96, 451 (1995).Google Scholar
6.Li, L., Li, G., Che, Y., and Su, W., Chem. Mater. 12, 2567 (2000).CrossRefGoogle Scholar
7.Feng, S., Li, G., Li, L., and Li, X., Rev. High Pressure Sci. Technol. 7, 1362 (1998).CrossRefGoogle Scholar
8.Hays, C.C., Zhou, J.S., Markert, J.T., and Goodenough, J.B., Phys. Rev. B 60, 10367 (1999).CrossRefGoogle Scholar
9.Sunstrom, J.E. and Kauzlarich, S.M., Chem. Mater. 5, 1539 (1993).CrossRefGoogle Scholar
10.Yamamoto, H., Tahara, T., Sugagara, Y., Kuroda, K., and Kato, C., Phase Transitions 41, 137 (1993).CrossRefGoogle Scholar
11.McLune, W.F., editor, Powder Diffraction File: Inorganic Phases: JCPDS International Center for Powder Diffraction Data, Swarthmore, PA, Card No. 9–127, 34–596, 1989.Google Scholar
12.Anderson, M.T., Greenwood, K.B., Tailor, G.A., and Poeppelmeimer, K.R., Progr. Solid State Chem. 122, 197 (1993).CrossRefGoogle Scholar
13.Li, L., Li, G., Song, X., and Su, W., Chin. Phys. Lett. 15, 925 (1998).CrossRefGoogle Scholar
14.Su, W., Liu, X., Jin, M., Xu, W., Wu, D., and Liu, M., Phys. Rev. B 37, 35 (1988).Google Scholar
15.Croft, M., Hodges, J.A., Kemmly, E., Krishnan, A., Murgai, V., and Gupta, L.C., Phys. Rev. Lett. 48, 826 (1982).CrossRefGoogle Scholar
16.Raffius, H., Mosel, B.D., Muller, W.W., Pegelow, U., Hadenfeldt, J.W., and Vomhof, T., J. Phys. Chem. Solids 55, 219 (1994).CrossRefGoogle Scholar
17.Stadnik, Z.M., Stroink, G., and Arakawa, T., Phys. Rev. B 44, 12552 (1988).CrossRefGoogle Scholar
18.Chien, C.L., DeBenedetli, S., and De S. Barros, F., Phys. Rev. B 10, 3913 (1974).CrossRefGoogle Scholar
19.Gibb, T.C., J. Chem. Soc. Dalton. Trans. 2245 (1981).CrossRefGoogle Scholar
20.Jin, M., Liu, X., Zhang, W., and Su, W., Solid State Commun. 76, 985 (1990).Google Scholar
21.Liu, X., Jin, M., and Liu, M., Hyperfine Interact. 68, 237 (1991).CrossRefGoogle Scholar
22.Warren, W.L., Seager, C.H., Dimos, D., and Friebele, E.J., Appl. Phys. Lett. 61, 253 (1992).Google Scholar
23.Bykev, I.P., Glinchuk, M.D., Skorokhod, V.V., and Kurland, V.M., Ferroelectrics 127, 89 (1992);CrossRefGoogle Scholar
Huang, J., Chasteen, N.D., and Fitzgerald, J.J., Chem. Mater. 10, 2848 (1998).Google Scholar
24.Li, L., Li, G., Smith, R.L. Jr., and Inomata, H., Chem. Mater. 12, 3705 (2000).CrossRefGoogle Scholar
25.Van Fleck, J.H., Phys. Rev. 74, 1168 (1948).CrossRefGoogle Scholar
26.Kutty, T.R.N., Murugaraj, P., and Gajbhiye, N.S., Mater. Res. Bull. 20, 565 (1985).CrossRefGoogle Scholar
27.Kutty, T.R.N., Murugaraj, P., and Gajbhiye, N.S., Mater. Lett. 2, 396 (1984).CrossRefGoogle Scholar
28.David, R.L., editor, CRC Handbook of Chemistry and Physics, 74th ed. (CRC Press, Boca Raton, FL), Table 8–21.Google Scholar
29.Bauminger, E.R., Diamant, A., Felver, I., Nowik, I., and Ofer, S., Phys. Lett. A50, 321 (1974).CrossRefGoogle Scholar
30.Chien, C.L. and Sleight, A.W., Phys. Rev. B 18, 2031 (1978).CrossRefGoogle Scholar