- 著者
- Sivasubramanian V. Kojima S.
- 出版者
- American Physical Society
- 雑誌
- Physical review B (ISSN:10980121)
- 巻号頁・発行日
- vol.85, no.5, pp.054104, 2012-02
- 被引用文献数
- 20 7
Brillouin spectra measurements have been carried out from 800 to 100 K for Pb(Sc1/2Ta1/2)O3 in back-scattering geometry. The frequency of the longitudinal acoustic (LA) phonon begins to show marked softening followed by an increase in its width below the intermediate temperature T* = 450 K. The gradual increase in the width of the LA phonon below T* is attributed to the electrostrictive coupling between the local polarization and strain. The frequency of the LA phonon mode exhibits anomalous behavior around 295 K, the phase transition temperature. The width of the LA phonon exhibits a sharp Landau-Khalatnikov-like maximum at 295 K. A central peak begins to appear around T* and exhibits critical slowing down upon further cooling. The relaxation times calculated for the LA phonon and central peak indicate the order-disorder nature of the phase transition.