Dielectric response of the relaxor ferroelectric Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} in the nonergodic state after a DC electric field is turned off
- A. Mickiewicz University, Institute of Physics (Poland)
The Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} (PMN) relaxor system is used as an example to analyze the temperature dependences of the low-frequency dielectric permitivity ({epsilon}'(T)) measured during zero-field heating (ZFH) from T = 10 K to T = 300 K after using different field cooling (FC) conditions. No changes in the temperature dependences of the permittivity have been detected during the transition from a nonergodic relaxor state (NERS) into an ergodic relaxor state (ERS) (at T{sub f} {approx} 216 K). However, the difference {delta}{epsilon}'(T) between the curves corresponding to different field cooling conditions in the same electric field has different shapes and different values below and above T {sup {yields}} (T{sub f} + 9 K){sup -} (for E{sub dc} = 1.52 kV/cm). The reduced permittivities {epsilon}'{sub r}(T, f) recorded under different cooling conditions are shown to change their behavior when passing through T = T{sub f} + 9 K. In NERS, these curves diverge: the stronger the field (0 {<=} E{sub dc} {<=} 3 kV/cm), the larger the divergence. In ERS, however, the {epsilon}'{sub r}(T, f) curves coincide under different cooling conditions irrespective of the field. The character of the changes in {delta}{epsilon}'(T) and {epsilon}'{sub r} (T, f) during the NERS-ERS transition is frequency-independent. The difference in the behavior of the dielectric response during ZFH after cooling in different (ZFC, FC) modes (even in a weak field), for both transition through T{sub f} and cooling down to T = 10 K, indicates different NERSs forming under these conditions. The contribution to {epsilon}'(T) from slowly relaxing regions ({omega} {approx} 0.1 mHz), whose polarization is reoriented after the field is turned off, is responsible for the fact that, during the NERS-ERS transition, the {epsilon}'{sub r}(T, f) curves coincide at a temperature that is higher than T = T{sub f}.
- OSTI ID:
- 21055081
- Journal Information:
- Journal of Experimental and Theoretical Physics, Vol. 102, Issue 6; Other Information: DOI: 10.1134/S1063776106060082; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ferroelectric domain wall relaxation in Ba{sub 0.25}Sr{sub 0.75}TiO{sub 3} films displaying Curie-Weiss behavior
First-order magnetic phase transition in (Er, Tb)M{sub 2}(M=Co, Ni) (abstract)