Effect of Zr doping on dielectric properties and grain boundary response of CdCu3Ti4O12 ceramics

2018 ◽  
Vol 44 (16) ◽  
pp. 20311-20321 ◽  
Author(s):  
Zhanhui Peng ◽  
Pengfei Liang ◽  
Yichen Xiang ◽  
Hui Peng ◽  
Xiaolian Chao ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Grain Boundary

scholarly journals Effects of Charge Compensation on Colossal Permittivity and Electrical Properties of Grain Boundary of CaCu3Ti4O12 Ceramics Substituted by Al3+ and Ta5+/Nb5+

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3294
Author(s):  
Jakkree Boonlakhorn ◽  
Jedsada Manyam ◽  
Pornjuk Srepusharawoot ◽  
Sriprajak Krongsuk ◽  
Prasit Thongbai
Keyword(s):  
Dielectric Properties ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Barrier Height ◽  
Potential Barrier ◽  
Charge Compensation ◽  
Solid State Reaction Method ◽  
Wide Frequency Range ◽  
Potential Barrier Height

The effects of charge compensation on dielectric and electrical properties of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics (x = 0−0.05) prepared by a solid-state reaction method were studied based on the configuration of defect dipoles. A single phase of CaCu3Ti4O12 was observed in all ceramics with a slight change in lattice parameters. The mean grain size of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics was slightly smaller than that of the undoped ceramic. The dielectric loss tangent can be reduced by a factor of 13 (tanδ ~0.017), while the dielectric permittivity was higher than 104 over a wide frequency range. Impedance spectroscopy showed that the significant decrease in tanδ was attributed to the highly increased resistance of the grain boundary by two orders of magnitude. The DFT calculation showed that the preferential sites of Al and Nb/Ta were closed together in the Ti sites, forming self-charge compensation, and resulting in the enhanced potential barrier height at the grain boundary. Therefore, the improved dielectric properties of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics associated with the enhanced electrical properties of grain boundaries. In addition, the non-Ohmic properties were also improved. Characterization of the grain boundaries under a DC bias showed the reduction of potential barrier height at the grain boundary. The overall results indicated that the origin of the colossal dielectric properties was caused by the internal barrier layer capacitor structure, in which the Schottky barriers at the grain boundaries were formed.

Influence of Grain and Grain-Boundary Resistances on Dielectric Properties of KNbO3 Under Small DC Bias Field

2013 ◽  
Vol 96 (10) ◽  
pp. 3127-3132
Author(s):  
Sankaramangalam Ulhas Sharath ◽  
Rajesh Kumar Singh ◽  
  Raghvendra ◽  
Bheeshma Pratap Singh ◽  
Pravin Kumar ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Grain Boundary ◽  
Bias Field ◽  
Dc Bias ◽  
Dc Bias Field

Direct Correlations of Grain Boundary Potentials to Chemical States and Dielectric Properties of Doped CaCu3Ti4O12 Thin Films

2018 ◽  
Vol 10 (18) ◽  
pp. 16203-16209 ◽  
Author(s):  
Ahra Cho ◽  
Chan Su Han ◽  
Meenjoo Kang ◽  
Wooseok Choi ◽  
Jihwan Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Grain Boundary ◽  
Chemical States

Aspects Determining the Dielectric Properties of SiC-Based Ceramic Grain-Boundary Capacitors

2002 ◽  
Vol 224-226 ◽  
pp. 27-30
Author(s):  
R. Zhang ◽  
Lian Gao ◽  
Hai Long Wang ◽  
Hong Liang Xu ◽  
Jing Kun Guo
Keyword(s):  
Dielectric Properties ◽  
Grain Boundary

Electrical/Dielectric Properties of Nanocrystalline Cerium Oxide

1996 ◽  
Vol 457 ◽  
Author(s):  
Jin-Ha Hwang ◽  
Thomas O. Mason ◽  
Edward J. Garboczi
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Grain Boundary ◽  
Transport Properties ◽  
Cerium Oxide ◽  
High Resistance ◽  
Current Flow ◽  
Impedance Spectra ◽  
Electrode Interface ◽  
Microcrystalline Material

ABSTRACTElectrical/dielectric properties of nanocrystalline cerium oxide have been studied using impedance spectroscopy, thermopower, and DC 4-point conductivity. The combined techniques identified the effect of poor electroding on impedance spectra. Incomplete contact between the specimen and the electrode induces an additional arc in the impedance spectra. The additional high resistance feature results from the geometric constriction of current flow at the specimen/electrode interface and can be misinterpreted as a grain boundary response. The defect chemistry, nonstoichiometry, and transport properties were investigated in nanoscale ceria and compared with those of microcrystalline material.

Cobalt oxide addition effects on the microstructure and electronic properties of CuZn ferrites

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000131-000138
Author(s):  
Hsing-I Hsiang ◽  
Jui-Huan Tu ◽  
Wen-Chin Kuo ◽  
Chi-Yao Tsai ◽  
Li-Then Mei
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Cobalt Oxide ◽  
Solid State Reaction ◽  
Copper Ions ◽  
Oxide Addition ◽  
Second Phases ◽  
Space Polarization

The effects of cobalt oxide addition on the microstructure and electrical properties of CuZn ferrites were investigated. CuZn ferrites with compositions of (CuO)0.2(ZnO)0.8(Co3O4)x/3 (Fe2O3) 0.986-2x; x = 0 , 0.02, 0.04, 0.08, 0.1 were synthesized using a solid state reaction. It was observed that the addition of cobalt will change the amounts and distribution of Cu2+, Cu+, Fe2+, and Fe3+ in the grain and grain boundary. The segregation of copper ions at the grain boundary was observed as the substitution of cobalt was increased. Moreover, as the x value was increased above 0.04, second phases of CuO and ZnO were found. The different amounts and distribution of Cu2+, Cu+, Fe2+, and Fe3+ in the bulk and grain boundary for samples added with different amounts of cobalt changed the conductivity activation energies of the bulk and grain boundary, and hence affected the space polarization and dielectric properties.

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