Temperature evolution of the local order parameter in relaxor ferroelectrics (1 – x)PMN–xPZT

Abstract

The temperature dependence of the local order parameter and relaxation time distribution function have been determined in (1 – x)PMN–xPZT ceramic samples via dielectric permittivity. Above the Burns temperature, the permittivity was found to follow the Currie–Weiss law, and with temperature decreasing the deviation was observed to increase. A local order parameter was calculated from the dielectric data using a modified Landau–Devonshire approach. These results are compared to the distribution function of relaxation times. It was found that a glasslike freezing of reorientable polar clusters occurs in the temperature range of diffuse relaxor transition. The evolution of the studied system to more ordered state arises from the increased PZT content. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

High‐Temperature Dielectric Relaxation in Pb(Mg1/3Nb2/3)O3–PbTiO3 Single Crystals

“…Hence, it is the true relaxor behavior. The high‐temperature anomaly, however, appears at a temperature higher than the well‐known Burns temperature (~600 K), hence, it has nothing to do with the diffuse ferroelectric phase transition. It is a pseudo‐relaxor behavior.…”

Distinctive contributions to dielectric response of relaxor ferroelectric lead scandium niobate ceramic system

“…While the main frame of Fig. shows the results in the temperature interval where the data have actually been fitted, the inset shows the same results over broader temperature range in the form which is commonly used to linearize the data –one reported way to determine the Burns temperature, where polar nanoregions should start to form in relaxor systems, is namely to observe the temperature at which the mean‐field fit starts to deviate from experimental points . It can be however seen that at lower temperatures also the fit with the universal scaling ansatz deviates from the experimental points –this is simply due to the fact that by decreasing the temperature, i.e., approaching the dispersive dynamic relaxor maximum, the experimental data themselves start to deviate from the intrinsic, i.e., static ones.…”

Low‐frequency 1/f noise in relaxor ferroelectric PMN–PZT

“…the dispersion becomes weaker as x in (1 -х)PMN-хPZT is increased. This shows the attenuation of relaxation properties in the relaxor system studied [8,9].…”