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Soft-phonon Dynamics in the Isotopically Induced Ferroelectric Phase Transition of Strontium Titanate

Published online by Cambridge University Press:  01 February 2011

Toshirou Yagi
Affiliation:
Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, JAPAN
Masaru Kasahara
Affiliation:
Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, JAPAN
Yuhji Tsujimi
Affiliation:
Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, JAPAN
Hiroki Hasebe
Affiliation:
Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, JAPAN
Masashi Yamaguchi
Affiliation:
University of California Riverside, Riverside, CA 92521-0403, U.S.A.
Ruiping Wang
Affiliation:
Smart Structure Center, National Institute for Advanced Industrial Science and Technology, Tsukuba 305-8568, JAPAN
Mitsuru Itoh
Affiliation:
Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, JAPAN
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Abstract

Abtract:

The ferroelectric phase transition of SrTi18O3 (STO8), where the quantum paraelectricity is reduced by the exchange of oxygen atoms 16O for its isotope 18O, has been studied by both Brillouin scattering and Raman scattering. The Brillouin spectra of the c44 and c66 modes in the paraelectric-tetragonal phase show anomalous behavior in the temperature region several degrees above TC accompanied by a central peak. The characteristic shape of the central peak indicates a coupling mechanism between the acoustic mode and an overdamped soft polar mode. Though the ferroelectric soft A2u mode is Raman inactive in the paraelectric phase, it has been observed in the x(yz)-x geometry indicating a local symmetry breaking above TC. Existence of the ferroelectric micro region in the temperature range far above TC is confirmed by the broad spectral component. The soft mode dynamics is concluded in the phase transition of STO18. The doublet spectrum is observed without any of considerable change by the isotope exchange.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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References

[1] Itoh, M., Wang, R., Inaguma, Y., Yamaguchi, T., Shan, Y-J. and Nakamura, T., Phys.Rev.Lett. 82, 3540 (1999).Google Scholar
[2] Wang, R. and Itoh, M., Phys.Rev. B62, 731 (2000).Google Scholar
[3] Itoh, M. and Wang, R., Appl.Phys.Lett. 76, 221 (2000).Google Scholar
[4] Muller, K.A. and Burkard, H., Phys.Rev. B19, 3593 (1979).Google Scholar
[5] Muller, K.A., Berlinger, W. and Tosatti, E., Z.Phys. B84, 277 (1991).Google Scholar
[6] Kleemann, W., Dec, J. and Westwanski, B., Phys.Rev. B58, 8985 (1998).Google Scholar
[7] Yamaguchi, M., Yagi, T., Wang, R. and Itoh, M., Phys.Rev. B63-17, 2102 (2001).Google Scholar
[8] Tsujimi, Y., Hasebe, H., Wang, R., Itoh, M. and Yagi, T., Ferrolectrics 261, 213 (2001).Google Scholar
[9] Kasahara, M., Wang, R., Itoh, M. and Yagi, T., J.Phys.Soc.Jpn. 70, 648 (2001).Google Scholar
[10] Yagi, T., Kasahara, M., Tsujimi, Y., Yamaguchi, M., Hasebe, H., Wang, R. and Itoh, M., Ferroelectrics 266, 489 (2002).Google Scholar
[11] Kasahara, M., Wang, R., Itoh, M. and Yagi, T., J.Phys.Soc.Jpn. 71 (2002) in print.Google Scholar
[12] Yamaguchi, M., Yagi, T., Wang, R. and Itoh, M., Phys.Rev. B65 (2002) in print.Google Scholar
[13] Uwe, H., Yamaguchi, H. and Sakudo, T., Ferroelectrics 96, 123 (1989).Google Scholar
[14] Uwe, H., Lyons, K.B., Carter, H.L. and Fleury, P.A., Phys.Rev. B33, 6436 (1986).Google Scholar
[15] Fleury, P.A., Scott, J.F. and Worlock, J.M., Phys.Rev.Lett. 21, 16 (1968).Google Scholar