TY - JOUR
T1 - Analysis of polarization behavior in relaxation of BaTiO3-based ferroelectrics using wideband dielectric spectroscopy
AU - Teranishi, Takashi
AU - Hoshina, Takuya
AU - Takeda, Hiroaki
AU - Tsurumi, Takaaki
N1 - Funding Information:
Manuscript received december 27, 2009; accepted June 20, 2010. This work was supported by the Grant-in-aid for scientific research of the Japan society for the Promotion of science. The authors are with the Graduate school of science and Engineering, Tokyo Institute of Technology, Tokyo, Japan (e-mail: teranishi.t.aa@ m.titech.ac.jp). digital object Identifier 10.1109/TUFFc.2010.1667
PY - 2010/10
Y1 - 2010/10
N2 - Wideband dielectric spectra from the kilohertz to terahertz range are discussed for BaTiO3-based ferroelectrics. Ceramics of BaTiO3 (BT), Ba0.6Sr0.4TiO3 (BST-0.6), and BaZr0.25Ti0.75O3 (BZT-0.25) were selected as normal ferroelectrics, ferroelectrics with diffuse phase transition (DPT ferroelectrics), and relaxor ferroelectrics, respectively. The variation of ionic polarization in both BT and BST-0.6 ceramics with temperature could be explained by the softening of the soft phonon mode. In BZT-0.25, a permittivity anomaly at the dielectric maximum temperature (Tm) at low frequencies is not attributed to the softening of the soft phonon mode, but originates from the permittivity derived from the εdipole polarization (dipole). Relaxor behavior in BZT-0.25 is derived from the increase in the depression of εdipole on cooling across the Tm with increasing frequency. In εdipole polarization, BT, BST- 0.6, and BZT-0.25 all exhibited a similar tendency of εdipole above the Curie temperature (Tc) and Tm. However, behavior of εdipole below the Tc can be explained by the ferroelectric domains in BT, whereas the variation of εdipole below the Tm could be explained by growth process of polar nanoregions (PNRs) in BST-0.6 and BZT-0.25. Regarding this, BT can be distinguished from BST-0.6 and BZT-0.25. Relaxation in BT could be interpreted as successive change in polarization mechanism from normal ferroelectrics to relaxor ferroelectrics via DPT ferroelectrics.
AB - Wideband dielectric spectra from the kilohertz to terahertz range are discussed for BaTiO3-based ferroelectrics. Ceramics of BaTiO3 (BT), Ba0.6Sr0.4TiO3 (BST-0.6), and BaZr0.25Ti0.75O3 (BZT-0.25) were selected as normal ferroelectrics, ferroelectrics with diffuse phase transition (DPT ferroelectrics), and relaxor ferroelectrics, respectively. The variation of ionic polarization in both BT and BST-0.6 ceramics with temperature could be explained by the softening of the soft phonon mode. In BZT-0.25, a permittivity anomaly at the dielectric maximum temperature (Tm) at low frequencies is not attributed to the softening of the soft phonon mode, but originates from the permittivity derived from the εdipole polarization (dipole). Relaxor behavior in BZT-0.25 is derived from the increase in the depression of εdipole on cooling across the Tm with increasing frequency. In εdipole polarization, BT, BST- 0.6, and BZT-0.25 all exhibited a similar tendency of εdipole above the Curie temperature (Tc) and Tm. However, behavior of εdipole below the Tc can be explained by the ferroelectric domains in BT, whereas the variation of εdipole below the Tm could be explained by growth process of polar nanoregions (PNRs) in BST-0.6 and BZT-0.25. Regarding this, BT can be distinguished from BST-0.6 and BZT-0.25. Relaxation in BT could be interpreted as successive change in polarization mechanism from normal ferroelectrics to relaxor ferroelectrics via DPT ferroelectrics.
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U2 - 10.1109/TUFFC.2010.1667
DO - 10.1109/TUFFC.2010.1667
M3 - Article
C2 - 20889394
AN - SCOPUS:77957693089
VL - 57
SP - 2118
EP - 2126
JO - Transactions of the IRE Professional Group on Ultrasonic Engineering
JF - Transactions of the IRE Professional Group on Ultrasonic Engineering
SN - 0885-3010
IS - 10
M1 - 5587388
ER -