The elastic properties of KF-substituted perovskite lead titanate(PbTiO_(3))were investigated by dielectric measurements and Brillouin light scattering.The ferroelectric phase transition occurred at substantially lowe...The elastic properties of KF-substituted perovskite lead titanate(PbTiO_(3))were investigated by dielectric measurements and Brillouin light scattering.The ferroelectric phase transition occurred at substantially lower temperature due to KF substitution,which was attributed to the modification of the covalency in Pb–O and Ti–O bonds.The longitudinal acoustic(LA)mode of KF-substituted PbTiO_(3) showed a frequency softening in the paraelectric phase,which was accompanied by increasing acoustic damping.This indicated that polarization fluctuations responsible for the acoustic anomalies were enhanced by KF substitution.展开更多
The electrostrictive properties above Te max represented by the field-related and polarization-related M and Q coefficients have been measured for PbZr_(1-x)Sn_(x)O_(3)single crystals with ani-ferroelectric phase tran...The electrostrictive properties above Te max represented by the field-related and polarization-related M and Q coefficients have been measured for PbZr_(1-x)Sn_(x)O_(3)single crystals with ani-ferroelectric phase transitions.The investigations presented in this paper have proved that the M_(11)(T)and Q_(11)(T)runs bring direct information of the pre-transitional effects connected with the co-existence of local polar objects with nonpolar matrix.Due to this co-existence,nonlinear Q_(11)(T)dependence in the neighborhood of T_(C)has been detected.Observed even in a wide tem-perature above T_(C),this co-existence is a natural feature of the material with ABO_(3)perovskite structure that undergoes structural transition to po lar phase.展开更多
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(Grant No.2013R1A1A2006582)JSPS KAKENHI(Grant No.26790040 and 25400329).
文摘The elastic properties of KF-substituted perovskite lead titanate(PbTiO_(3))were investigated by dielectric measurements and Brillouin light scattering.The ferroelectric phase transition occurred at substantially lower temperature due to KF substitution,which was attributed to the modification of the covalency in Pb–O and Ti–O bonds.The longitudinal acoustic(LA)mode of KF-substituted PbTiO_(3) showed a frequency softening in the paraelectric phase,which was accompanied by increasing acoustic damping.This indicated that polarization fluctuations responsible for the acoustic anomalies were enhanced by KF substitution.
文摘The electrostrictive properties above Te max represented by the field-related and polarization-related M and Q coefficients have been measured for PbZr_(1-x)Sn_(x)O_(3)single crystals with ani-ferroelectric phase transitions.The investigations presented in this paper have proved that the M_(11)(T)and Q_(11)(T)runs bring direct information of the pre-transitional effects connected with the co-existence of local polar objects with nonpolar matrix.Due to this co-existence,nonlinear Q_(11)(T)dependence in the neighborhood of T_(C)has been detected.Observed even in a wide tem-perature above T_(C),this co-existence is a natural feature of the material with ABO_(3)perovskite structure that undergoes structural transition to po lar phase.
