scholarly journals Colossal Permittivity and Multiple Effects in (Zn + Ta) co-doped TiO2 Ceramics

2020 ◽  
Author(s):  
Jiangtao Fan ◽  
TianTian Yang ◽  
Zhenzhu Cao

Abstract The search for giant dielectric constant materials is imperative because of their potential for important applications for the areas of device miniaturization and energy storage. In this work, we report a (Zn + Ta) co-doped TiO2 (ZTTO) ceramics that manifests high dielectric permittivity (>104) and low dielectric loss. This dielectric property shows a high stability in wide temperature range (25-200℃) and frequency range(20-106Hz). The crystalline structure, microstructure and dielectric properties of ZTTO ceramics were systematically investigated. XPS, Impedance spectroscopy and frequency dependent dielectric constant under DC bias results reveal that the colossal dielectric properties of (Zn2+1/3Ta5+2/3)xTi1-xO2 ceramics were mainly caused by electron-pinned defect-dipoles (EPDD) model, internal barrier layer capacitance (IBLC) effect and electrode effect. This work would provide a guidance to further researching the colossal permittivity CP materials.

2016 ◽  
Vol 34 (2) ◽  
pp. 322-329 ◽  
Author(s):  
Wan Q. Cao ◽  
Ling F. Xu ◽  
Mukhlis M. Ismail ◽  
Li L. Huang

AbstractBaTiO3 ceramics doped with 0.40 mol% NaNbO3 were prepared using a traditional approach by sintering at temperature of 1250 °C to 1290 °C. The prepared ceramics was characterized by very good dielectric properties, such as high dielectric constant (1.5 × 105), low dielectric loss (0.1), and good dielectric temperature stability in the −40 °C to 100 °C range for the sample sintered below 1270 °C. The dielectric characteristics obtained with XPS confirmed that Ti4+ ions remain in the state without any change. The huge increase in dielectric constant in NaNbO3 doped BaTiO3 samples occurs when large amount of Ba2+ ions are excited to a high energy bound state of Ba2+ − e or Ba+ to create electron hopping conduction. For samples with the content of NaNbO3 higher than 0.40 mol%, or sintering temperature higher than 1280 °C, compensation effect is dominated by cation vacancies with sharply decreasing dielectric constant and increased dielectric loss. The polaron effect is used to explain the relevant mechanism of giant dielectric constant appearing in the ferroelectric phase.


2017 ◽  
Vol 866 ◽  
pp. 277-281
Author(s):  
Naphat Albutt ◽  
Suejit Pechprasarn ◽  
Pattaraporn Damkoengsuntorn ◽  
Thanapong Sareein

In this work, the uses of giant dielectric constant of Y2NiMnO6 ceramics were investigated in the frequency range from 1 kHz to 3 MHz. The Y2NiMnO6 ceramics were sintered at 1400 °C for 6, 12, 18 and 24 hours, respectively. The dielectric properties of Y2NiMnO6 ceramics were examined in dc bias from 0 to 1.5 volt at room temperature. We found that all sintering times displayed high dielectric permittivity at frequencies below 105 Hz, above which the values decreased significantly, applied dc bias also reduced dielectric permittivity. The peak of dielectric loss decreased significantly at high dc bias due to decreased contribution of dc conductivity in grain ceramics. This research has characterised electrical properties of Y2NiMnO6 ceramics which maybe suitable for electronic components including batteries and capacitors.


2016 ◽  
Vol 18 (35) ◽  
pp. 24270-24277 ◽  
Author(s):  
Mei-Yan Tse ◽  
Xianhua Wei ◽  
Jianhua Hao

Our work shows contributions to the high-performance dielectric properties, including a CP of up to 104–105 and a low dielectric loss down to 0.03 in (Er0.5Nb0.5)xTi1−xO2 materials with secondary phases.


2019 ◽  
Vol 7 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Biao Zhao ◽  
Mahdi Hamidinejad ◽  
Chongxiang Zhao ◽  
Ruosong Li ◽  
Sai Wang ◽  
...  

A microcellular structure can effectively tune the dielectric properties of PVDF/carbon composite foams.


2011 ◽  
Vol 687 ◽  
pp. 251-256 ◽  
Author(s):  
Ying He ◽  
Huai Wu Zhang ◽  
Yuan Xun Li ◽  
Wei Wei Ling ◽  
Yun Yan Wang ◽  
...  

CaCu3Ti4O12 ceramics doped with 0-2.0 wt% Li2CO3 were prepared by the solid-state reaction, and their electric and dielectric properties were investigated. It is found that these ceramics had the properties of high dielectric constant and comparatively low dielectric loss. At the doping amount of 0.5 wt%, the dielectric constant is kept to be 105 with weak frequency dependence below 105 Hz, and its loss tangent (tan δ) is suppressed below 0.1 between 300 Hz-5 kHz (with the minimum value of 0.06 at 1 kHz from 218 K to 338 K). The impedance spectroscopy analysis confirms that the decrease of dielectric loss is mainly due to the increase of resistance in the grain boundary, which may be related to the influence of Ti4O7 secondary phase. Our result indicates that doping Li2CO3 is an efficient method to optimize the dielectric properties of CaCu3Ti4O12.


2004 ◽  
Vol 847 ◽  
Author(s):  
Milind Arbatti ◽  
Xiaobing Shan ◽  
Z.-Y. Cheng

ABSTRACTA ceramic-powder polymer composite, making use of a newly developed ceramics - CaCu3Ti4O12 (CCTO) - that has a giant dielectric constant as the filler, is developed. In this work, poly(vinylidene fluoride - trifluoroethylene) [P(VDF-TrFE)] 55/45 mol% copolymer was used as matrix. It is found that the wettability between the copolymer and CCTO is poor, which makes the solution cast composites have a poor uniformity. The uniformity and thus the dielectric constant of the composites can be significantly improved by using hot-press technology to form “sandwich” structure. It is also found that the thermal annealing process can improve the dielectric constant of the composite. The experimental data show that for the flexible composites the dielectric constant at 1 kHz can reach more than 300 at room temperature and more than 700 at ∼70 °C.


2007 ◽  
Vol 280-283 ◽  
pp. 85-88
Author(s):  
Lin Hu ◽  
He Ping Zhou ◽  
Hao Xue ◽  
Chun Lai Xu

Barium strontium titanium oxide (BSTO) has great advantages and potentiality for the application of microwave technology. In order to be used in phased array antennas, high dielectric tunability, relatively low dielectric constant and low dielectric loss are required. In this paper, MgO was mixed into BSTO and the microstructure and dielectric properties of MgO-mixed BSTO bulk ceramics were investigated. The mole ratio of Ba and Sr was rather fixed to 5:5 in this study. It is observed that a small amount of MgO (5 wt%) has gone beyond the solubility limits of Mg in BSTO. The dielectric constant and dielectric loss of BSTO ceramics decreased with the increase of the content of MgO mixed. However, the tunability of MgO-mixed BSTO ceramics decreased at the same time. 20wt% MgO-mixed BSTO ceramics exhibits preferable dielectric properties with acceptable tunability.


2016 ◽  
Vol 18 (28) ◽  
pp. 19183-19193 ◽  
Author(s):  
Cuijiao Zhao ◽  
Xiaonan Wei ◽  
Yawen Huang ◽  
Jiajun Ma ◽  
Ke Cao ◽  
...  

Although general porous materials have a low dielectric constant, their uncontrollable opened porous structure results in high dielectric loss and poor barrier properties, thus limiting their application as interconnect dielectrics.


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