scholarly journals CaZn1/3Nb2/3O3-based dielectric ceramics for silver co-sintering applications

2012 ◽  
Vol 44 (3) ◽  
pp. 299-305
Author(s):  
A. Chaouchi ◽  
M. Saidi ◽  
S. d’Astorg ◽  
S. Marinel
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Glass Phase ◽  
Perovskite Oxide ◽  
Complex Perovskite ◽  
Low Dielectric ◽  
Silver Electrodes ◽  
Dielectric Ceramics ◽  
High Dielectric ◽  
B2o3 Glass

The Ca(Zn1/3Nb2/3)O3 (CZN) complex perovskite oxide has been studied for its attractive dielectric properties (?r=34, Qxf=15 890GHz, ?f=-48 ppm.?C-1) for applications such as multilayer ceramics capacitors or hyperfrequency resonators. Nevertheless, high temperatures (>1250?C) are required to obtain well dense CZN ceramic, prohibiting any silver co-sintering (Tf (Ag) = 961?C). For that reason, the sintering temperature lowering of CZN by glass phase?s additions has been investigated. This material is finally sinterable at low temperature with combined glass phase -lithium salt additions, and exhibits, at 1MHz, very low dielectric losses, a relatively high dielectric constant with a good stability versus temperature. The 2%weight of ZnO-SiO2-B2O3 glass phase and 1%wt of LiF added CZN sample sintered at 920?C exhibits a relative density higher than 95% and attractive dielectric properties: a dielectric constant ?r of 22, low dielectrics losses (tan (?)< 10-3), a temperature coefficient of the permittivity ??<100 ppm.?C-1, and an insulating resistivity higher than 1013?.cm. Its interesting properties and its co-sinterability with silver electrodes make this ceramic suitable for L.T.C.C applications.

scholarly journals Low temperature sintered ZnTio3 dielectric ceramics with temperature coefficient of dielectric constant near zero

2010 ◽  
Vol 4 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Ahcéne Chaouchi ◽  
Sadia Kennour ◽  
Sophie D'Astorg ◽  
Sylvain Marinel ◽  
Mohamed Aliouat
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Temperature Coefficient ◽  
High Frequency ◽  
Glass Phase ◽  
Sintering Aids ◽  
Glass Addition ◽  
Dielectric Ceramics ◽  
B2o3 Glass ◽  
Multilayer Dielectric

ZnTiO3 compound is an attractive dielectric ceramics owing to its interesting dielectric properties in high frequency range (?r = 19, QXf = 30,000GHz, ?? ? + 120 ppm/?C). The structure, microstructure and dielectric properties of sintered ZnTiO3, with a mixture of ZnO-B2O3 glass phase and CuO oxide as sintering aids, have been investigated. For all compounds, the sintering temperature becomes 850?C due to the glass addition. It is also shown that the addition of CuO oxide allows a control of the temperature coefficient of the permittivity (??). This parameter varies from positive to negative values with increasing the CuO content. The ZnTiO3 composition sintered at 850?C with 5 wt.% ZnO-B2O3 glass phase and 2.2 wt.% CuO addition exhibits attractive dielectric properties (?r = 23, tan ? < 10-3 and a temperature coefficient of the dielectric constant near zero, ?? = 3 ppm/?C) at 1 MHz. All these properties lead this system compatible for manufacturing Ag based electrodes multilayer dielectrics devices needed for LTCC application or other multilayer dielectric components. .

X7R type lead complex perovskite ferroelectric ceramics with high dielectric constant

1998 ◽  
Vol 13 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Lijian Ruan ◽  
Longtu Li ◽  
Zhilun Gui
Keyword(s):  
Dielectric Constant ◽  
High Dielectric Constant ◽  
Temperature Stability ◽  
Ferroelectric Ceramics ◽  
Complex Perovskite ◽  
Two Phase ◽  
Dielectric Ceramics ◽  
High Dielectric ◽  
Lead Complex ◽  
Sintering Method

A new X7R type dielectric ceramics for the PMN-BT-PT system with a high dielectric constant (4832) and a low firing temperature (1100–1130 °C) was prepared by the mixed-sintering method. The results of XRD, SEM, EDAX, and dielectric measurements showed that the dielectric ceramics is a two-phase composite with the high dielectric constant originating from the ferroelectric relaxor, and the temperature stability of the dielectric properties from two-phase coexistence.

Dielectric Properties of Li-Doped CaCu3Ti4O12 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 251-256 ◽  
Author(s):  
Ying He ◽  
Huai Wu Zhang ◽  
Yuan Xun Li ◽  
Wei Wei Ling ◽  
Yun Yan Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Secondary Phase ◽  
Doping Amount ◽  
Spectroscopy Analysis ◽  
Low Dielectric ◽  
Tan Δ ◽  
High Dielectric ◽  
Impedance Spectroscopy Analysis

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.

Ga2O3-Doped ZnO-Nb2O5-TiO2 Dielectric Resonators for Terrestrial and Space Telecommunications Applications

2016 ◽  
Vol 869 ◽  
pp. 79-84 ◽  
Author(s):  
Maria do Carmo de Andrade Nono ◽  
Pedro José Castro ◽  
E.G.L. Rangel ◽  
Sergio Luiz Mineiro
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Dielectric Resonators ◽  
Crystalline Phases ◽  
Low Dielectric ◽  
Gallium Doping ◽  
Doped Zno ◽  
Dielectric Ceramics ◽  
Quality Factor Q

Dielectric ceramics find application as dielectric resonators (DRs) in communications systems operating at microwave frequencies. RDs for this application require a unique set of properties: high value of the dielectric constant, low dielectric loss and high frequency stability. This paper presents an investigation of the correlation between the dielectric properties, the characteristics of microstructure and the crystalline phases of Ga2O3-doped ZnO-Nb2O5-TiO2 ceramic system. The ceramics sintered at 1200 °C were characterized as for density, crystalline phases, microstructure and microwave dielectric properties. The results showed that these dielectric ceramics, obtained from the TiO2 anatase crystalline structure, present dielectric constant and quality factor (Q) values appropriate for their use as dielectric resonators in microwave circuits. According to the experiments, as the gallium doping has raised, the dielectric constant increased, the Q factor decreased and the temperature coefficient had a tendency to decrease to a certain extent.

Influence of MgO Content on Microstructure and Dielectric Properties in (BaSr)TiO3 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 85-88
Author(s):  
Lin Hu ◽  
He Ping Zhou ◽  
Hao Xue ◽  
Chun Lai Xu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Low Dielectric Constant ◽  
Microwave Technology ◽  
Phased Array Antennas ◽  
Strontium Titanium Oxide ◽  
Low Dielectric ◽  
Barium Strontium ◽  
High Dielectric

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.

Preparation and unique dielectric properties of nanoporous materials with well-controlled closed-nanopores

2016 ◽  
Vol 18 (28) ◽  
pp. 19183-19193 ◽  
Author(s):  
Cuijiao Zhao ◽  
Xiaonan Wei ◽  
Yawen Huang ◽  
Jiajun Ma ◽  
Ke Cao ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Porous Structure ◽  
Barrier Properties ◽  
Nanoporous Materials ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
High Dielectric Loss ◽  
High Dielectric

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.

Dielectric ceramics in the BaO–Sm2O3–TiO2–Ta2O5 quaternary system

2000 ◽  
Vol 15 (1) ◽  
pp. 125-129 ◽  
Author(s):  
X. M. Chen ◽  
Z. Y. Xu ◽  
J. Li
Keyword(s):  
Dielectric Constant ◽  
Temperature Coefficient ◽  
Quaternary System ◽  
High Dielectric Constant ◽  
Tungsten Bronze ◽  
Complex Phase ◽  
Low Dielectric ◽  
Unknown Phase ◽  
Dielectric Ceramics ◽  
High Dielectric

Dielectric ceramics in the BaO–Sm2O3–TiO2–Ta2O5 quaternary system were prepared and characterized for five typical compositions: BaSm5Ti7Ta3O30, Ba2Sm4Ti6Ta4O30, Ba3Sm3Ti5Ta5O30, Ba4Sm2Ti4Ta6O30, and Ba5SmTi3Ta7O30. The latter three compositions tended to form the tungsten–bronze phase, and the ceramics based on these compositions had a high dielectric constant (134–175) and a low dielectric loss (on the order of 10−3) but a larger temperature coefficient of the dielectric constant. Meanwhile, the former two compositions generally had a more complex phase constitution, containing the tungsten–bronze phase combined with some unknown phase, and a relatively small temperature coefficient of the dielectric constant in the temperature range of 20 to 85 °C could be achieved in these two compositions.

Effect of Pb Volatilization on Dielectric Properties of 0.77PbMg1/3(Nb0.9Ta0.1)2/3O3-0.23PbTiO3

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3738-3744 ◽  
Author(s):  
C. Zhang ◽  
J. T. Wang ◽  
M. Q. Qian ◽  
T. P. Chen ◽  
I. Akujobi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Lead Magnesium Niobate ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
Dielectric Constant And Loss ◽  
Different Temperatures ◽  
Lead Magnesium ◽  
High Dielectric ◽  
The Cost

Lead magnesium niobate-lead titanate (PMN-PT) is an intriguing candidate for applications in many electronic devices such as multi-layer capacitors, electro-mechanical transducers etc. because of its high dielectric constant, low dielectric loss and high strain near the Curie temperature. As an extension of our previous work on Ta-doped PMNT-PT aimed at optimizing the performance and reducing the cost, this paper focuses on the effect of Pb volatilization on the dielectric properties of 0.77 Pb ( Mg 1/3( Nb 0.9 Ta 0.1)2/3) O 3-0.23 PbTiO 3. The dielectric constant and loss of the samples are measured at different frequencies and different temperatures. The phase purity of this compound is determined by X-ray diffraction pattern. It is found that the volatilization during sintering does influence the phase formation and dielectric properties. The best condition is sintering with 0.5 g extra PbO around a 4 g PMNT-PT sample.

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

2020 ◽  
Author(s):  
Jiangtao Fan ◽  
TianTian Yang ◽  
Zhenzhu Cao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Low Dielectric ◽  
Giant Dielectric ◽  
High Dielectric Permittivity ◽  
Colossal Permittivity ◽  
Giant Dielectric Constant ◽  
High Dielectric ◽  
Device Miniaturization ◽  
Co Doped

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.

scholarly journals Modified halloysite nanotube filled polyimide composites for film capacitors: high dielectric constant, low dielectric loss and excellent heat resistance

RSC Advances ◽  
2018 ◽  
Vol 8 (19) ◽  
pp. 10522-10531 ◽  
Author(s):  
Tianwen Zhu ◽  
Chao Qian ◽  
Weiwen Zheng ◽  
Runxin Bei ◽  
Siwei Liu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Halloysite Nanotubes ◽  
Halloysite Nanotube ◽  
Low Dielectric ◽  
The Matrix ◽  
Polyimide Composites ◽  
High Dielectric

Halloysite nanotubes (HNTs) were chosen as the fillers and polyimide (PI) as the matrix to form a series of composites with excellent dielectric properties and thermostabilities.

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