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. .

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.

Dielectric properties of La-substituted Pb0.5Ca0.5[(Mg1/3Nb2/3)0.5Ti0.5]O3 ceramics

2001 ◽  
Vol 16 (7) ◽  
pp. 2053-2056
Author(s):  
X. J. Lu ◽  
X. M. Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Microwave Dielectric Properties ◽  
Present Approach ◽  
Calculated Temperature ◽  
Microwave Dielectric ◽  
La Substitution ◽  
Dielectric Ceramics

Modification of Pb0.5Ca0.5[(Mg1/3Nb2/3)0.5Ti0.5]O3 dielectric ceramics was performed by up to 20 mol% La substitution for Pb and Ca. The temperature coefficient of dielectric constant was significantly reduced by the present approach, while an increased Qf factor was achieved. Good microwave dielectric properties were obtained in a composition Pb0.425Ca0.425La0.1[(Mg1/3Nb2/3)0.5Ti0.5]O3: ε = 125; Qf = 3150 GHz; calculated temperature coefficient of resonant frequency δf = +253 ppm/°C.

Microstructural and Dielectric Responses of Calcium Copper Titanate Added Soda-Lime Glass for High Frequency Devices

2020 ◽  
Vol 1010 ◽  
pp. 233-238
Author(s):  
Mohd Fariz Ab Rahman ◽  
Mohd Fadzil Ain ◽  
Julie Juliewatty Mohamed ◽  
Siti Roshayu binti Hassan ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
High Frequency ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Glass Addition ◽  
Calcium Copper Titanate ◽  
High Frequency Devices ◽  
Xrd Patterns

The microstructures and dielectric responses of calcium copper titanate (CCTO) ceramics with soda-lime glass addition was investigated. The addition of soda lime glass was varied from 0-5 wt.% by solid-state reaction. The dielectric properties of CCTO indicated that dielectric constant was increased while dielectric loss was decreased after glass addition. The SEM micrographs showed the grain size of CCTO was decreased while the grain boundaries area of CuO + glass were increased after the addition of soda-lime glass. Both XRD patterns of CCTO and CCTO-soda lime glass sintered samples showed the formation of CCTO phase with minor peaks of CuO phase, respectively. These results indicated that soda-lime glass addition gave a significant effect on the microstructural and dielectric responses of CCTO ceramics.

Optimization of Dielectric Properties of Glass Added BaxSr1-xTiO3 Ceramics for Pulsed Power Applications

2010 ◽  
Vol 654-656 ◽  
pp. 1990-1993 ◽  
Author(s):  
Qing Meng Zhang ◽  
Lei Wang ◽  
Jun Luo ◽  
Qun Tang ◽  
Jun Du
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Breakdown Strength ◽  
Frequency Stability ◽  
Pulsed Power ◽  
Glass Addition ◽  
Impedance Analyzer ◽  
Low Dielectric ◽  
B2o3 Glass

BaxSr1-xTiO3 (0.2≤x≤0.5) ceramics with 10 vol% BaO-SiO2-B2O3 glass addition were prepared. The microstructure and dielectric properties were investigated by XRD, SEM, ferroelectric tester and impedance analyzer. The results show that with the decrease of x, the pulse breakdown strength of the samples is increased, and the dielectric constant and dielectric loss is decreased gradually. In the frequency from 10 kHz to 20 MHz, the dielectric constant of all the samples show good frequency stability. For x=0.2, the samples exhibit high breakdown strength of 37.7 kV/mm, moderate dielectric constant of 311 and low dielectric loss of 5×10-4,which is a promising dielectric for pulsed power applications.

Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.92Zr0.08]O3−δ Ceramics with Glass Addition

2014 ◽  
Vol 556-562 ◽  
pp. 318-321
Author(s):  
Gang Xiong
Keyword(s):  
Dielectric Properties ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Glass Content ◽  
Glass Addition ◽  
Microwave Dielectric ◽  
Resonator Frequency

The effects of ZnO-B2O3-Na2O(ZBN) glass on the sinterability and microwave dielectric properties of Ca [(Li1/3Nb2/3)0.92Zr0.08]O3−δ −0.05TiO2 ceramics were investigated . ZBN glass doping can effectively reduce sintering temperatue by 100~150oC. The temperature coefficient of resonator frequency τf increased with an increase of ZBN glass content and sintering temperatue. When ZBN glass of 1.8wt% were added, the optimum microwave dielectric properties: εr=32.8, Qf =13420GHz and τf= − 4.3×10−6/oC were obtained at the sintering temperature of 1000oC.

Sintering behavior and dielectric properties of BaTiO3 added with BaO-Bi2O3-B2O3 glass phase

2018 ◽  
Vol 44 (11) ◽  
pp. 13004-13010 ◽  
Author(s):  
Tingting Li ◽  
Hiroyo Segawa ◽  
Naoki Ohashi
Keyword(s):  
Dielectric Properties ◽  
Glass Phase ◽  
Sintering Behavior ◽  
B2o3 Glass

Photosensitive Polyimide having low loss tangent for RF application

2018 ◽  
Vol 2018 (1) ◽  
pp. 000476-000482 ◽  
Author(s):  
Masao Tomikawa ◽  
Hitoshi Araki ◽  
Yohei Kiuchi ◽  
Akira Shimada
Keyword(s):  
Molecular Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Frequency ◽  
Low Dielectric Constant ◽  
Low Loss ◽  
Elongation At Break ◽  
Low Dielectric ◽  
The Poor

Abstract Progress of 5G telecommunication and mm radar for autopilot, high frequency operation is required. Insulator materials having low loss at high frequency is desired for the applications. We designed the low dielectric constant, and low dielectric loss materials examined molecular structure of the polyimide and found that permittivity 2.6 at 20GHz, dielectric loss 0.002. Furthermore, in consideration of mechanical properties such as the toughness and adhesion to copper from a point of practical use. Dielectric properties largely turned worse when giving photosensitivity. To overcome the poor dielectric properties, we designed the photosensitive system. After all, we successfully obtained 3.5 of dielectric constant and 0.004 of dielectric loss, and 100% of elongation at break. In addition, we offered a B stage sheet as well as varnish. These materials are applicable to re-distribution layer of FO-WLP, Interposer and other RF applications for microelectronics.

scholarly journals Investigation of AC-Measurements of Epoxy/Ferrite Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 492 ◽  
Author(s):  
Moustafa A. Darwish ◽  
Alex V. Trukhanov ◽  
Oleg S. Senatov ◽  
Alexander T. Morchenko ◽  
Samia A. Saafan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
High Frequency ◽  
Precipitation Method ◽  
Semiconductor Behavior ◽  
Ferrite Composites ◽  
Co Precipitation ◽  
Theoretical Results ◽  
Composite Samples

A pure ferrite and epoxy samples as well as the epoxy/ferrite composites with different 20 wt.%, 30 wt.%, 40 wt.%, and 50 wt.% weight ferrite contents have been prepared by the chemical co-precipitation method. AC-conductivity and dielectric properties such as the dielectric constant and dielectric loss of the prepared samples have been studied. The obtained results showed that the samples had a semiconductor behavior. The dielectric constant of the composites has been calculated theoretically using several models. For the composite sample that contains 20 wt.% of ferrites, these models give satisfactory compliance, while for the composite samples with a higher percentage of nanofillers, more than 30 wt.% theoretical results do not coincide with experimental data. The investigated polymer has very low conductivity, so this type of polymer can be useful for high-frequency applications, which can reduce the losses caused by eddy current. Thus, the prepared samples are promising materials for practical use as elements of microwave devices.

Microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti) ceramics

1999 ◽  
Vol 14 (9) ◽  
pp. 3567-3570 ◽  
Author(s):  
Ji-Won Choi ◽  
Chong-Yun Kang ◽  
Seok-Jin Yoon ◽  
Hyun-Jai Kim ◽  
Hyung-Jin Jung ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Multiphase Materials ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

The microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti, 0 ≤ x ≤ 0.5) ceramics were investigated. In general, the ceramics prepared were multiphase materials. However, single-phase specimens having orthorhombic perovskite structure similar to CaTiO3 could be obtained in the vicinity of Sn = 0.2 to 0.3, and Ti = 0.2. As Sn concentration increased, the dielectric constant (εr) decreased and the quality factor (Q) significantly increased within the limited Sn concentration. As Ti concentration increased, the dielectric constant (εr) increased, the quality factor (Q) decreased, and the temperature coefficient of resonant frequency (τf) changed from a negative to positive value. The temperature coefficient of resonant frequency of 0 ppm/°C was realized at Ti = 0.2. The Q · fo value and εr for this composition were found to be 26100 GHz and 38.6, respectively.

Structure and Microwave Dielectric Properties of (Ca0.9375Sr0.0625)0.25 (Li0.5Sm0.5)0.75TiO3 Ceramics with B2O3-CuO Sintering Aids

2011 ◽  
Vol 284-286 ◽  
pp. 1442-1446
Author(s):  
Yue Ming Li ◽  
Zong Yang Shen ◽  
Zhu Mei Wang ◽  
Hua Zhang ◽  
Yan Hong ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramics ◽  
Sintering Aids ◽  
Oxide Mixture ◽  
High Permittivity ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The B2O3-CuO oxide mixture (abbreviated as BC) was selected to lower the sintering temperature of (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (abbreviated as CSLST) microwave dielectric ceramics by solid sate reaction technique. The effects of BC doping amounts on the crystal structure, microstructure and microwave dielectric properties of the ceramics were investigated. For the ceramic sample with the composition of CSLST + 5 wt% BC, its sintering temperature was reduced to 1000 °C as compared to 1200 °C for pure CSLST. In addition to the obtained good microwave dielectric properties as follows: εr = 80.4, Q×f = 1380 GHz, τf = -32.89 ×10-6/°C, this ceramic was a desirable high-permittivity microwave dielectric candidate for low-temperature cofired ceramic (LTCC) applications.

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