Relaxor and incipient ferroelectric phases in 6.5/65/35 PLZT ceramics

The linear and third harmonic nonlinear dielectric constants were measured in 6.5/65/35 PLZT hot-pressed ceramics. Linear dielectric data obtained on ooling show the transition from an ergodic to a nonergodic relaxor phase while, on heating, a ferroelectric to ergodic relaxor phase transition appears. The third harmonic di-electric response is reminiscent of an ergodic to nonergodic relaxor phase transition. Existence of the spontaneous polarization below the Vogel-Fulcher temperature at which the longest relaxation time diverges, indicates the possibility that the sample breaks up at low temperatures into relaxor glass-like and ferroelectric order dominated regions. (C) 2003 Elsevier Ltd. All rights reserved.