- 著者
- Ohta Ryu Zushi Junta Ariizumi Takuma Kojima Seiji
- 出版者
- American Institute of Physics
- 雑誌
- Applied physics letters (ISSN:00036951)
- 巻号頁・発行日
- vol.98, no.9, pp.092909, 2011-02
- 被引用文献数
- 36
The precursor dynamics of a cubic–tetragonal ferroelectric phase transition of potassium tantalate niobate (KTa1−xNbxO3 with x = 0.32) crystals is studied by Brillouin scattering. The appearance of the central peak (CP) and marked softening of the elastic constant c11 are clearly observed above the Curie temperature, TC–T, owing to the interaction between the LA mode and local polarization fluctuations of polar nanoregions (PNRs). The relaxation time determined by the CP width clearly shows a critical slowing down above TC–T, indicating an order–disorder feature of the ferroelectric phase transition. The size of a dynamic PNR is evaluated, and it increases toward TC–T.