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Critical evolution of the local order parameters related to the nanopolar domains in Pb(Mg1/3Nb2/3)O3 ceramics.
- Source :
- Applied Physics A: Materials Science & Processing; Nov2009, Vol. 97 Issue 3, p587-594, 8p, 1 Diagram, 9 Graphs
- Publication Year :
- 2009
-
Abstract
- In the present paper, Pb(Mg<subscript>1/3</subscript>Nb<subscript>2/3</subscript>)O<subscript>3</subscript> (PMN) ceramics prepared by the columbite method were investigated. The dielectric study indicates typical relaxor properties, with a frequency dispersion in the range of 200–350 K. The relaxor-to-paraelectric phase transition was evidenced by the continuous decrease of the local order parameter derived from the permittivity-temperature data. As a result of the critical behavior, the main Raman modes show anomalies at: (i) ∼150 K; (ii) ∼220 K (i.e. close to the critical temperature reported for the field-induced ferroelectric state in PMN single crystal); (iii) ∼260 K (i.e. the temperature of the permittivity maximum); (iv) ∼350 K (the temperature for initiation of the cluster freezing process T<superscript>*</superscript>); (v) ∼620 K (Burns temperature). The frequency split of the doublet at ∼605 and ∼500 cm<superscript>−1</superscript> presents a critical behavior related to the local symmetry lowering and to the structure ordering due to a phase transformation which takes place below T<superscript>*</superscript>. The tunability in the paraelectric state was interpreted in terms of reorientation of the non-interacting nanopolar clusters in a double-well potential. The temperature dependence of the nanopolar domain size also shows anomalies in the range of T<superscript>*</superscript>. The size and dynamics of the polar nanodomains is essential in determining the functional properties of the Pb(Mg<subscript>1/3</subscript>Nb<subscript>2/3</subscript>)O<subscript>3</subscript> relaxor. [ABSTRACT FROM AUTHOR]
- Subjects :
- PHASE transitions
CERAMICS
DIELECTRICS
LEAD
FERROELECTRIC devices
Subjects
Details
- Language :
- English
- ISSN :
- 09478396
- Volume :
- 97
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Applied Physics A: Materials Science & Processing
- Publication Type :
- Academic Journal
- Accession number :
- 44984628
- Full Text :
- https://doi.org/10.1007/s00339-009-5258-3