Distributions of relaxation times in relaxor ferroelectric Ba(Ti_0.8 Ce_0.2)O₃

Abstract

The dielectric behavior of the Ba(Ti_0.8Ce_0.2)O₃ ceramics was studied by broadband dielectric spectroscopy in a temperature interval 140–500 K. The broad dielectric relaxation was analyzed by the Havriliak–Negami relationship and the distribution of relaxation times formalism. It was found that the Havriliak–Negami average relaxation time, longest and most probable relaxation times from the distribution of relaxation times follow the Vogel–Fulcher law. The freezing temperature of the longest relaxation time is substantially higher than the freezing temperature of the most probable relaxation time, indicating the distribution of freezing temperatures. The dielectric dispersion has all features inherent to relaxor ferroelectrics and the relaxation is assigned to the dynamics of polar nanoregions.

Keywords:

• Dielectric spectroscopy
• relaxor ferroelectrics
• barium titanate
• distribution of relaxation times

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by the Research Council of Lithuania (LMTLT), agreement No. S-LB-19-5. L. M. acknowledges the Romanian PN-III-P4-IDPCE-2016-0817 grant.