A Raman Scattering Study in Relaxor Pb(Zn 1/3 Nb 2/3 )O 3 -PbTiO 3 Solid Solutions

Dielectric Anisotropy near Morphotropic Phase Boundary in Pb(Zn1/3Nb2/3)O3–xPbTiO3 Crystals

“…The details of the preparation of PZN-xPT were already described elsewhere. 21,22,27) In our measurement of dielectric anisotropy, two methods [electrostatic force microscopy (EFM) and macroscopic measurement of dielectric constant] were adopted.…”

“…11) It was reported on the basis of the Raman scattering experiment that no softening of the optical mode near the MPB in PZN-xPT is observed in the temperature range where the dielectric constant as a function of temperature shows a peak. [21][22][23] Nakata and coworkers 24,25) reported on the basis of the central peak measurement in PZN-xPT that polarization fluctuation, belonging to the E-irreducible representation in the rhombohedral 3 m or tetragonal 4 mm phase, appears in the GHz region, implying that the relaxation mode of the dielectric dispersion perpendicular to the spontaneous polarization exists. Kamba et al 26) reported that the dielectric dispersion in the relaxor (Pb 1Àx La x )-(Zr y Ti 1Ày )O 3 measured in a wide frequency range (20 Hz-100 THz) shows the relaxation mode with a wide-range distribution of the relaxation frequency.…”

Phase diagram and Raman imaging of grain growth mechanisms in highly textured Pb(Mg1/3Nb2/3)O3–PbTiO3 piezoelectric ceramics

“…Note also that Mg/Nb substitution and PMN/PT phase mixing lead to an increase of the low-wavenumber band intensity, as observed on heating ion-conducting perovskites (26). Conversely, this effect is reduced under pressure (20,21). We can expect the unit-cell expansion observed on heating or by decreasing pressure to promote stronger dipoles and the intensity of the low-wavenumber region can probably be used as a parameter to measure the relaxor degree.…”