Soft-phonon mode observation in Li 2Ge 4O 9 phase above room temperature

Yoshihiro Takahashi, Jun Kunitomo, Kensaku Nakamura, Minoru Osada, Takumi Fujiwara

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7 Citations (Scopus)

Abstract

Li 2Ge 4O 9 is known to be a ferroelectric phase with Curie temperature at T c ∼ -93 C. In this study, we found both the lowest-frequency phonon and heat-capacity anomalies around 100 C in the Li 2Ge 4O 9 phase, demonstrating their presence in the structural phase-transition. The phase transition is probably triggered by regularization of distorted GeO 6 octahedra in the paraelectric phase, resulting in another phase consisting of the regular octahedral GeO 6 unit, which was supported by in situ measurement of emission of 2E → 4A 2 transition in the Mn 4-doped phase. It is deduced that the phase transition is more dynamic than ferroelectric phase-transition originating in ordering of the Li ions.

Original languageEnglish
Article number091902
JournalApplied Physics Letters
Volume100
Issue number9
DOIs
Publication statusPublished - 2012 Feb 27
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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    Takahashi, Y., Kunitomo, J., Nakamura, K., Osada, M., & Fujiwara, T. (2012). Soft-phonon mode observation in Li 2Ge 4O 9 phase above room temperature. Applied Physics Letters, 100(9), [091902]. https://doi.org/10.1063/1.3688603