Low‐temperature Maxwell‐Wagner relaxation in (Na + Nb) co‐doped rutile TiO2 colossal permittivity ceramics

The exact mechanism of the stunning colossal permittivity behavior found in (donor‐acceptor) co‐doped TiO2 system still remains enigmatic. This behavior results from a thermally activated dielectric relaxation occurring below 50 K. Herein, thermally stimulated depolarization current analysis combine...

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Bibliographic Details
Published in:Journal of the American Ceramic Society 2020-03, Vol.103 (3), p.1839-1845
Main Authors: Wang, Chunchang, Li, Tianyu, Xie, Yuanmiao, Wang, Jin
Format: Article
Language:English
Subjects:
Ceramics
Dielectric properties
Dielectric relaxation
low temperature
Permittivity
Thermally stimulated depolarization current
Titanium dioxide
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Summary:The exact mechanism of the stunning colossal permittivity behavior found in (donor‐acceptor) co‐doped TiO2 system still remains enigmatic. This behavior results from a thermally activated dielectric relaxation occurring below 50 K. Herein, thermally stimulated depolarization current analysis combined with dielectric investigation was used to disentangle this relaxation in (Na + Nb) co‐doped TiO2 ceramics. We find that this relaxation is related to frozen electrons and features the Vogel‐Fulcher behavior and negative dielectric tunability. Our results reveal that this low‐temperature relaxation is a new kind of Maxwell‐Wagner relaxation. Differences between the low‐temperature Maxwell‐Wagner relaxation and its high‐temperature counterpart are discussed. This study provides new insights into the physics of the eye‐catching dielectric properties in co‐doped TiO2 system.
ISSN:0002-7820
1551-2916
DOI:10.1111/jace.16883