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Lattice Dynamics, Dielectric Constants, and Phase Diagram of Bismuth Layered Ferroelectric Bi 3 Ti 1− x W x NbO 9+δ Ceramics
Author(s) -
Zhang Jinzhong,
Jiang Kai,
Zhou Zhiyong,
Hu Zhigao,
Wang Genshui,
Dong Xianlin,
Chu Junhao
Publication year - 2016
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14374
Subject(s) - aurivillius , raman spectroscopy , ferroelectricity , dielectric , materials science , phonon , phase diagram , bismuth , phase transition , ferroelectric ceramics , condensed matter physics , analytical chemistry (journal) , natural bond orbital , phase (matter) , mineralogy , chemistry , optics , physics , density functional theory , computational chemistry , optoelectronics , organic chemistry , chromatography , metallurgy
Lattice dynamics and phase transitions of Aurivillius ferroelectric Bi 3 Ti 1− x W x NbO 9+δ ( BTWN 100 x , 0 ≤ x ≤ 15%) ceramics have been investigated by temperature‐dependent Raman spectra (80–800 K) and far‐infrared (FIR) reflectance spectra (6–300 K). The frequency, intensity, and line width of phonon modes as well as complex dielectric functions of BTWN 100 x ceramics have been extracted by fitting Raman and FIR reflectance spectra with the multi‐Lorentzian oscillator model. It was found that the dielectric constants at a certain frequency region become lower with increasing W compositions at room temperature due to the compressive stress on W–O bands. Moreover, the temperature‐dependent behavior of optical phonon modes in BTWN 100 x ceramics indicates that there are two intermediate phases during the phase transition from paraelectric I 4/ mmm to ferroelectric A 2 1 am phase on cooling. The phase diagram of BTWN 100 x ceramics as a function of W composition has been improved.