Origin of the dielectric response in Ba0.767Ca0.233TiO3

被引：14

作者：

Shimizu, Takao ^{[1
]}

Fu, Desheng ^{[2
]}

Taniguchi, Hiroki ^{[1
]}

Taniyama, Tomoyasu ^{[1
]}

Itoh, Mitsuru ^{[1
]}

机构：

[1] Tokyo Inst Technol, Mat & Struct Lab, Yokohama, Kanagawa 2268503, Japan

[2] Shizuoka Univ, Div Global Res Leaders, Hamamatsu, Shizuoka 4328561, Japan

来源：

APPLIED PHYSICS LETTERS | 2012年 / 100卷 / 10期

关键词：

SOFT-MODE SPECTROSCOPY; BARIUM-TITANATE; RAMAN SPECTRUM; BATIO3; DEPENDENCE; CRYSTALS;

D O I：

10.1063/1.3693524

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We perform a Raman scattering study to elucidate the mechanism of temperature independent dielectric response of Ba0.767Ca0.233TiO3 (BCTO-0.233) from a viewpoint of phonon dynamics. BCTO-0.233 remains tetragonal below T-c down to 3.5 K. Over-damped soft phonon observed in a pure BaTiO3 is found to become underdamped in BCTO-0.233, suggesting that local dipoles induced by Ca2+ off-centering suppress the hopping of Ti ions to reduce damping of the soft-mode. The temperature dependence of the soft-mode frequency agrees qualitatively with the dielectric permittivity through Lyddane-Sachs-Teller relationship, indicating that the dielectric response of BCTO-0.233 is governed by the soft-mode. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3693524]

引用

页数：4

共 27 条

[1] RAMAN STUDIES OF UNDERDAMPED SOFT MODES IN PBTIO3 [J].