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Journal of Materials Science

, Volume 41, Issue 1, pp 27–30 | Cite as

Polar nanoclusters in relaxors

  • R. BlincEmail author
  • V. V. Laguta
  • B. Zalar
  • J. Banys
Article

Abstract

The central problem in the physics of relaxors is the nature of the polar nanoclusters. Whereas relaxors are homogeneous at high enough temperatures, polar nanoregions immersed in a neutral matrix are formed below a certain temperature T b . This should lead to a two component system. Here we present direct microscopic evidence for the two component nature of relaxors. We show that the chemical shift perturbed 207Pb NMR spectra of these systems consist of an isotropic component corresponding to a spherical glassy matrix which does not respond to an applied electric field, and an anisotropic component, corresponding to frozen out polar nanoclusters which order in a strong enough electric field, forming a ferroelectric phase. This is as well reflected in the dynamic properties where the relaxation time distribution function starts to become asymmetric with decreasing temperature and a second maximum—which is never seen in dipolar glasses and is obviously due to polar clusters—appears on further cooling. We also show that the basic difference between dipolar glasses and relaxors is the fact that polar nanoclusters can be oriented in a strong enough electric field and a ferroelectric phase can be induced. This is not the case in dipolar glasses where the response is due to single dipoles which can not be ordered by applied electric fields.

Keywords

Electron Paramagnetic Resonance 207Pb Electron Paramagnetic Resonance Spectrum Ferroelectric Phase Single Dipole 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  1. 1.J. Stefan InstituteLjubljanaSlovenia
  2. 2.Institute for Problems of Materials ScienceUkrainian Academy of SciencesKievUkraine
  3. 3.Faculty of PhysicsVilnius UniversityVilniusLithuania

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