Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Spontaneous long and short-range ferroelectric ordering in Pb0.55La0.30TiO3 ceramics

Full text
Author(s):
Mastelaro, V. R. [1] ; Mascarenhas, Y. P. [1] ; Neves, P. P. [2] ; Mir, M. [2] ; Doriguetto, A. C. [2] ; Michalowicz, A. [3, 4] ; Moscovici, J. [3, 4] ; Lente, M. H. [5] ; Eiras, J. A. [5]
Total Authors: 9
Affiliation:
[1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Paulo - Brazil
[2] Univ Fed Alfenas UNIFAL MG, Lab Cristalog, BR-37130000 Alfenas, MG - Brazil
[3] CNRS, Inst Chim & Mat Paris Est, F-94320 Thiais - France
[4] Univ Paris Est Creteil, F-94320 Thiais - France
[5] Univ Fed Sao Carlos UFSCar, Dept Fis, BR-13565670 Sao Paulo - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Journal of Applied Physics; v. 107, n. 11 JUN 1 2010.
Web of Science Citations: 5
Abstract

In this work, we investigated the temperature dependence of short and long-range ferroelectric ordering in Pb0.55La0.30TiO3 relaxor composition. High-resolution x-ray powder diffraction measurements revealed a clear spontaneous macroscopic cubic-to-tetragonal phase transition in the PLT relaxor sample at similar to 60 K below the maximum of the dielectric constant peak (T-m). Indeed, the x-ray diffraction (XRD) data showed that at 300 K (above T-m but below the Burns temperature, T-B) the long-range order structure corresponds to a macroscopic cubic symmetry, space group number 221 (Pm-3m), whereas the data collected at 20 K revealed a macroscopic tetragonal symmetry, space group number 99 (P4mm) with c/a=1.0078, that is comparable to that of a normal ferroelectric. These results show that for samples with tetragonal composition, the long-range ferroelectric order may be recovered spontaneously at cryogenics temperatures, in contrast to ferroelectric samples with rhombohedral symmetry. On the other hand, x-ray absorption spectroscopy investigations intriguingly revealed the existence of local tetragonal disorder around Ti atoms for temperatures far below T-m and above T-B, for which the sample presents macroscopic tetragonal and cubic symmetries, respectively. (C) 2010 American Institute of Physics. {[}doi: 10.1063/1.3431024] (AU)

FAPESP's process: 00/09722-9 - Ferroelectric materials: phenomenology, properties and characterization
Grantee:José Antonio Eiras
Support type: Research Projects - Thematic Grants