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Giant Dielectric Permittivity Properties and Relevant Mechanism of NaCu 3 Ti 3 SbO 12 Ceramics
Author(s) -
Hao Wentao,
Zhang Jialiang,
Tan Yongqiang,
Zhao Minglei,
Wang Chunglei
Publication year - 2011
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.04197.x
Subject(s) - permittivity , dielectric , ceramic , materials science , mechanism (biology) , dielectric permittivity , composite material , condensed matter physics , mineralogy , engineering physics , optoelectronics , chemistry , physics , quantum mechanics
A series of NaCu 3 Ti 3 SbO 12 ceramics were prepared by the conventional solid‐state reaction technique under different sintering temperature conditions. Their crystalline structure, microstructure, dielectric properties, and complex impedance were systematically investigated. It has been found that they are in general quite similar to CaCu 3 Ti 4 O 12 ceramics reported in the literature, showing giant dielectric permittivity properties with ɛ′ as high as 10 4 . Within the measuring frequency range of 40–100 MHz, a single dielectric relaxation with the characteristic frequency around 1 MHz is seen at room temperature or below, whereas an additional one in the low‐frequency region is also observed at high temperatures. Dielectric properties and microstructures change largely with sintering temperature, and a small amount of CuO secondary phase and Cu 2+ /Cu + , Ti 4+ /Ti 3+ and Sb 5+ /Sb 3+ aliovalences exist in these NaCu 3 Ti 3 SbO 12 ceramics. On the basis of an electrode comparison experiment, the two dielectric relaxations are ascribed to an internal barrier layer capacitance effect and an electrode polarization effect, respectively.