High Dielectric Constant Polymer Ceramic Composites

1999 ◽  
Vol 600 ◽  
Author(s):  
Y. Bai ◽  
V. Bharti ◽  
Z.-Y. Cheng ◽  
H. S. Xu ◽  
Q. M. Zhang
Keyword(s):  
Dielectric Constant ◽  
Relative Dielectric Constant ◽  
Ceramic Composites ◽  
Dielectric Behavior ◽  
Breakdown Field ◽  
Clean Environment ◽  
The Matrix ◽  
High Dielectric ◽  
Breakdown Field Strength ◽  
Room Temperature Dielectric Constant

AbstractA new polymer-ceramic composite, using the newly developed relaxor ferroelectric polymer that has a high room temperature dielectric constant as the matrix, is reported. Different kinds of ceramic powders were studied and homogeneous composite thin films (20μm) were fabricated. It was observed that the increase of the dielectric constant of the composites with the ceramic content could be described quite well by the expression developed by Yamada et al., when the ceramic content is below 60% by volume. The experimental data shows that the relative dielectric constant of composites using PMN-PT powders can reach more than 250 with weak temperature dependence (i.e., the dielectric constant changes little in a broad temperature range). In addition to high permittivity, the composite prepared in clean environment also has high breakdown field strength (120MV/m), which yields an energy storage density more than 14J/cm3. The dielectric behavior of the composite at various frequencies was also studied and the results show that the material is promising for high frequency applications.

High Breakdown Field Dielectric Elastomer Actuators Using Encapsulated Polyaniline as High Dielectric Constant Filler

2010 ◽  
Vol 20 (19) ◽  
pp. 3280-3291 ◽  
Author(s):  
Martin Molberg ◽  
Daniel Crespy ◽  
Patrick Rupper ◽  
Frank Nüesch ◽  
Jan-Anders E. Månson ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
High Dielectric Constant ◽  
Dielectric Elastomer ◽  
Breakdown Field ◽  
Dielectric Elastomer Actuators ◽  
High Dielectric

Dielectric Behavior of Barium Titanate/Carbon Fibers Composites

2017 ◽  
Vol 898 ◽  
pp. 2101-2106
Author(s):  
Zhong Yang Wang ◽  
Xin Yan Li ◽  
Run Hua Fan ◽  
Pei Tao Xie ◽  
Kai Sun ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Carbon Fibers ◽  
Percolation Theory ◽  
High Dielectric Constant ◽  
Volume Fraction ◽  
Dielectric Behavior ◽  
Lower Volume Fraction ◽  
Lower Volume ◽  
High Dielectric

Conductor–insulator composites have been extensive researched for high dielectric constant. Most of them concentrated on metal polymers or metal ceramics. Barium titanate–carbon fibers composites were prepared by using a solid state reaction process with carbon fibers contents ranging from7 vol% to 23 vol%. Due to the high-aspect-ratio of carbon fiber, it was easy to produce a conducting network at much lower volume fraction. FESEM images illustrated that the carbon fibers influenced the densification and microstructure of the ceramics. Besides, addition of carbon fibers led to increase in dielectric permittivity, also had effects on the dielectric loss and ac conductivity. The dielectric and conductivity properties as a function of carbon fibers volume fraction were explained by the percolation theory.

Surface Micro Topographical and Dielectric Studies of Cholesterol Crystals

2013 ◽  
Vol 665 ◽  
pp. 289-296
Author(s):  
Poorvesh M. Vyas ◽  
Mihir J. Joshi
Keyword(s):  
Dielectric Constant ◽  
Acetic Acid Solution ◽  
Dielectric Behavior ◽  
Major Constituent ◽  
Dielectric Study ◽  
Cholesterol Crystals ◽  
Ir Studies ◽  
High Dielectric ◽  
Main Component ◽  
High Level

Cholesterol is a main component in mammalian cell membranes and lipoproteins. High level of cholesterol in blood can damage arteries and potentially linked with cardiovascular diseases. Cholesterol is also major constituent of gall stones. Cholesterol crystals were grown by single diffusion gel growth technique using neutral silica gel set by acetic acid. Solution of cholesterol prepared in acetone was poured as a supernatant solution on set gel. Transparent, thin, platelet type crystals were grown. Powder XRD and FT IR studies were carried out for the confirmation of crystal system and chemical bonding. The surface micro topographical study was carried out by using SEM and AFM and interesting features were observed. As cholesterol possesses high dielectric constant, it functions as an insulting cover for the transmission of electric impulses in the nervous tissues; therefore, the dielectric study was carried to understand its dielectric behavior in the frequency range from 50 Hz to 5 MHz. The dielectric constant decreased as the frequency of applied field increased. The a.c. conductivity and a.c. resistivity were also calculated.

Effect of Post Plasma Treatment on Reliability and Dielectric Properties of SiOF Films Deposited by ECRCVD With SiF4 and O2

1997 ◽  
Vol 476 ◽  
Author(s):  
Seoghyeong Lee ◽  
Jae-Yoon Yoo ◽  
Kyunghui Oh ◽  
Jong-Wan Park
Keyword(s):  
Dielectric Properties ◽  
Plasma Treatment ◽  
Silicon Oxide ◽  
Treatment Time ◽  
Relative Dielectric Constant ◽  
Breakdown Field ◽  
Plasma Treatment Time ◽  
Breakdown Field Strength ◽  
Thermal Stability Of

AbstractThe effect of post plasma treatment on dielectric properties and reliability of fluorine doped silicon oxide (SiOF) films were investigated by measuring their C-V and I-V characteristics, XPS, AFM, and AES. The post plasma treatment of SiOF films was carried out in-situ at 300 °C in the deposition chamber. In this research, when the post plasma treatment time increased, we obtained the following results: (1) The etch rate of SiOF films decreased from 80Å/sec to 10Å/sec. (2) Surface roughness of the plasma treated SiOF films was increased due to the ion bombardment effect of the plasma. (3) The refractive index and relative dielectric constant increased from 1.391 to 1.461 and 3.14 to 3.9, respectively, due to the changes of surface chemistry by the post plasma treatment. (4) The leakage current density of SiOF films prepared by ECRCVD using SiF4 and O2 was less than 1 × 10−9A/cm2. (5) The breakdown field strength increased from 3.5 MV/cm to 8 MV/cm. (6) The thermal stability of the Cu/TiN/SiOF/Si system remained stable up to 600 °C.

Microstructure-Electrical Propertyrelationships in Cement-Based Materialss

1994 ◽  
Vol 370 ◽  
Author(s):  
R.A. Olson ◽  
G.M. Moss ◽  
B.J. Christensen ◽  
J.D. Shane ◽  
R.T. Coverdale ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Freezing Point ◽  
Relative Dielectric Constant ◽  
Precise Determination ◽  
Dielectric Behavior ◽  
Dielectric Constants ◽  
Direct Result ◽  
Solvent Exchange ◽  
Early Hydration ◽  
Variable Nature

AbstractThere has been much recent progress on the application of impedance spectroscopy (IS) to the study of microstructure and transport in cement-based materials. The IS spectrum allows for the precise determination of bulk resistance, which is a measure of the pore phase interconnectivity, and calculation of the relative dielectric constant, which is related to the capillary pore size and distribution. High values of the relative dielectric constant (σ105) observed in cement paste at early hydration times are the direct result of the microstructure inducing dielectric amplification. Solvent exchange and freezing experiments, combined with digital-image-based computer modeling, have confirmed the role of large capillary pores in the dielectric amplification in young pastes.The conductivities (σ) and relative dielectric constants (εr) of ordinary portland cement (OPC) pastes were monitored during cooling and solvent exchange with isopropanol and methanol. Dramatic decreases in σ and εr, in some cases over two orders of magnitude, occurred at the initial freezing point of the aqueous phase in the macropores and large capillary pores. The same dramatic decreases in a and er were observed at the onset of solvent exchange. Both effects provide experimental support for the dielectric amplification mechanism within the microstructure on the μm-scale. A secondary dielectric amplification was observed in the frozen and solvent exchanged pastes, which produced dielectric constants on the order of 103. This effect is attributed to amplification on the nm-scale within the layered calcium silicate hydrate (C-S-H) gel microstructure. Additional insight into the variable nature of the C-S-H microstructure was obtained by comparing the dielectric behavior of methanol-exchanged OPC pastes to isopropanolexchanged OPC pastes.

Dielectric behavior of a flexible three-phase polyimide/BaTiO3/multi-walled carbon nanotube composite film

2016 ◽  
Vol 09 (01) ◽  
pp. 1650006 ◽  
Author(s):  
Junli Wang ◽  
Shengli Qi ◽  
Yiyi Sun ◽  
Guofeng Tian ◽  
Dezhen Wu
Keyword(s):  
Composite Film ◽  
Volume Fraction ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Dielectric Behavior ◽  
Low Dielectric ◽  
Three Phase ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
High Dielectric

A three-phase composite film was produced by inserting multi-walled carbon nanotubes (MWCNTs) and BaTiO3 nanoparticles into polyimide (PI). The combination of in-situ polymerization and water-based preparation involved in the experiment ensured fillers’ homogeneous dispersion in the matrix, which led to flexible shape of the composite films. The dielectric properties of composite films as a function of the frequency and the volume fraction of MWCNTs were studied. Such composite film displayed a high dielectric constant (314.07), low dielectric loss and excellent flexibility at 100[Formula: see text]Hz in the neighborhood of percolation threshold (9.02 vol%) owing to the special microcapacitor structure. The experimental results were highly consistent with the power law of percolation theory.

New High-Dielectric-Constant Polymer-Ceramic Composites

2004 ◽  
Vol 847 ◽  
Author(s):  
Milind Arbatti ◽  
Xiaobing Shan ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Ceramic Powder ◽  
Ceramic Composites ◽  
Flexible Composites ◽  
Giant Dielectric ◽  
Poly Vinylidene Fluoride ◽  
Solution Cast ◽  
Giant Dielectric Constant ◽  
High Dielectric

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.

scholarly journals Investigating the dielectric properties of barium titanate nanocomposites using transmission electron microscopy image processing

MRS Advances ◽  
2021 ◽  
Author(s):  
Gio Ferro ◽  
Dithi Ganjam ◽  
Maia Gibson ◽  
Katie Partington ◽  
Akshay Trikha ◽  
...  
Keyword(s):  
Image Processing ◽  
Dielectric Constant ◽  
Energy Storage ◽  
Barium Titanate ◽  
Computational Models ◽  
Transmission Electron Microscopy Image ◽  
Dielectric Behavior ◽  
Dielectric Constants ◽  
Transmission Electron ◽  
High Dielectric

AbstractBarium titanate (BTO) is a ferroelectric perovskite material used in energy storage applications because of its high dielectric constant. A previous study showed that the dielectric constant for BTO nanoparticles drastically increases to over 15,000 at a particle size of 70 nm. This result is highly contested, but its implications to energy storage motivated our investigation into the dielectric constants of BTO nanoparticles that are incorporated into a polymer matrix. We developed a novel method of using image processing techniques on transmission electron microscope images of BTO-polymer nanocomposites. Data on the positions, shapes, sizes, and orientations of BTO nanoparticles were used to build more realistic computational models that simulate the dielectric behavior of the nanocomposites. Here, we investigate the relationship between regions of enhanced electric field and the composite dielectric constant.

scholarly journals The Research of Conductivity and Dielectric Properties of ZnO/LDPE Composites with Different Particles Size

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4136 ◽  
Author(s):  
Yujia Cheng ◽  
Guang Yu ◽  
Boyang Yu ◽  
Xiaohong Zhang
Keyword(s):  
Dielectric Constant ◽  
Field Strength ◽  
Interfacial Polarization ◽  
Breakdown Field ◽  
Test Results ◽  
Nano Zno ◽  
Inorganic Particles ◽  
Zno Particles ◽  
Ldpe Composites ◽  
Breakdown Field Strength

Nanocomposites exhibit a high dielectric strength, whereas microcomposites exhibit a high thermal conductivity. In this study, good insulating materials were developed on the basis of the synergetic effect of micro- and nanoparticles, which were used as inorganic fillers. With a double-melting blend, nano-ZnO/low density polyethylene (LDPE), micro-ZnO/LDPE, and micro-nano-ZnO/LDPE composites were prepared, according to the scanning electron microscope test, polarization microscope test, conductivity test, breakdown test, and dielectric spectrum test, the dielectric property of micro-nano-ZnO/LDPE was explored. The SEM test results showed that by adding a suitable proportion of ZnO particles, the inorganic particles could disperse uniformly without reuniting. The PLM test results showed that the micro- and nano-ZnO particles adding decreased the crystal size. The arrangement was regular and tight. The macroscopic results showed that the mass fraction of nanoparticles and microparticles were 3% and 2%, the samples conductivity was the lowest. The breakdown field strength of the nanocomposites increased. The breakdown field strength of nanocomposites with 1%, 3%, and 5% nanoparticle contents were 5%, 15%, and 10% higher than that of pure LDPE. The addition of inorganic particles resulted in new polarization modes: Ionic displacement polarization and interfacial polarization. The ZnO/LDPE composites exhibited a higher dielectric constant and dielectric loss factor than pure LDPE. However, with the increasing frequency, it took considerable time to attain interfacial polarization in the nanocomposite and micro-nanocomposite, thus decreasing the dielectric constant.

scholarly journals Material Characterization of High Dielectric Constant Polymer–Ceramic Composite for Embedded Capacitor to RF Application

2002 ◽  
Vol 25 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Yang Rao ◽  
Jireh Yue ◽  
C. P. Wong
Keyword(s):  
Dielectric Constant ◽  
Breakdown Voltage ◽  
Ceramic Composite ◽  
High Dielectric Constant ◽  
Ceramic Composites ◽  
Nano Composite ◽  
Capacitance Density ◽  
High Breakdown Voltage ◽  
Embedded Capacitor ◽  
High Dielectric

Embedded capacitor technology can improve electrical performance and reduce assembly cost compared with traditional discrete capacitor technology. Polymer–ceramic composites have been of great interest as embedded capacitor material because they combine the processability of polymers with the desired electrical properties of ceramics. A novel nano-structure polymer–ceramic composite with very high dielectric constant (εr∼150, a new record for the highest reportedεrvalue of nano-composite) has been developed in our previous work. RF application of embedded capacitors requires that insulating material have high dielectric constant at high frequency (GHz), low leakage current, high breakdown voltage and high reliability. A set of electrical tests have been conducted in this work to characterize the properties of the in house developed novel high dielectric constant polymer–ceramic nano-composite. Results show that this material has faily high dielectric constant in the RF range, low electrical leakage and high breakdown voltage. 85/85 TH aging test has been performed and it had shown this novel high K material has good reliability. An embedded capacitor prototype with capacitance density of35 nF/cm2has been manufactured using this nano-composite with spinning coating technology. This novel nano-composite can be used for the integral capacitors in the RF applications.

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