Central Peak of Bismuth Layered Ferroelectrics Pb₂Bi₄Ti₅O₁₈ Studied by Brillouin Scattering

Abstract

Brillouin scattering spectra have been observed in ceramic sample of Bi-Layered Perovskites Pb ₂ Bi ₄ Ti ₅ O ₁₈ using a Sandercock type tandem Fabry-Perot interferometer. A central peak was observed in the spectrum, which shows the anomalous increase of relaxation time with approaching to T ₁ = 450 K. The temperature dependences of intensity and width in the central peak spectrum show anomaly at T ₂ = 740 K in addition to T ₁ . However, no anomalous behavior has been obtained at T _c = 583 K reported as a ferroelectric phase transition point with a dielectric measurement by E. C. Subbarao.

Keywords:

• Central peak
• ferroelectrics
• high resolution Raman scattering
• Brillouin scattering
• bismuth layered perovskites
• Pb₂Bi₄Ti₅O₁₈

Acknowledgments

This work was supported by a Grant-in-Aid for Scientific Research (B) from JSPS No. 17340088 and a Grant-in-Aid for Scientific Research (S) from JSPS No. 17104004.