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Significantly Improved Colossal Dielectric Properties and Maxwell-Wagner Relaxation of TiO2-Rich Na1/2Y1/2Cu3Ti4+xO12 Ceramics
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Document Title
Significantly Improved Colossal Dielectric Properties and Maxwell-Wagner Relaxation of TiO2-Rich Na1/2Y1/2Cu3Ti4+xO12 Ceramics
Author
Saengvong P, Chanlek N, Putasaeng B, Pengpad A, Harnchana V, Krongsuk S, Srepusharawoot P, Thongbai P
Name from Authors Collection
Affiliations
Khon Kaen University; National Science & Technology Development Agency - Thailand; National Metal & Materials Technology Center (MTEC); Khon Kaen University
Type
Article
Source Title
MOLECULES
Year
2021
Volume
26
Issue
19
Page
-
Open Access
gold, Green Published
Publisher
MDPI
DOI
10.3390/molecules26196043
Format
Abstract
In this work, the colossal dielectric properties and Maxwell-Wagner relaxation of TiO2-rich Na1/2Y1/2Cu3Ti4+xO12 (x = 0-0.2) ceramics prepared by a solid-state reaction method are investigated. A single phase of Na1/2Y1/2Cu3Ti4O12 is achieved without the detection of any impurity phase. The highly dense microstructure is obtained, and the mean grain size is significantly reduced by a factor of 10 by increasing Ti molar ratio, resulting in an increased grain boundary density and hence grain boundary resistance (R-gb). The colossal permittivities of epsilon' similar to 0.7-1.4 x 10(4) with slightly dependent on frequency in the frequency range of 10(2)-10(6) Hz are obtained in the TiO2-rich Na1/2Y1/2Cu3Ti4+xO12 ceramics, while the dielectric loss tangent is reduced to tan delta similar to 0.016-0.020 at 1 kHz due to the increased R-gb. The semiconducting grain resistance (R-g) of the Na1/2Y1/2Cu3Ti4+xO12 ceramics increases with increasing x, corresponding to the decrease in Cu+/Cu2+ ratio. The nonlinear electrical properties of the TiO2-rich Na1/2Y1/2Cu3Ti4+xO12 ceramics can also be improved. The colossal dielectric and nonlinear electrical properties of the TiO2-rich Na1/2Y1/2Cu3Ti4+xO12 ceramics are explained by the Maxwell-Wagner relaxation model based on the formation of the Schottky barrier at the grain boundary.
Funding Sponsor
National Research Council of Thailand (NRCT) [N41A640084]; Khon Kaen University
Publication Source
WOS