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In this work, eleven commercially available nanoparticles are benchmarked against each other according to their potential for an application in a polypropylene (PP) based nanocomposite for thin film power capacitors. Biaxially ori...
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In this work, eleven commercially available nanoparticles are benchmarked against each other according to their potential for an application in a polypropylene (PP) based nanocomposite for thin film power capacitors. Biaxially oriented films containing a fixed concentration of 5 wt%. Al2O3, TiO2, SiO2, or POSS nanoparticles with different surface functionalization were analyzed by dielectric spectroscopy and dielectric breakdown measurements. Two particle systems emerged to increase both the dielectric breakdown strength and the reliability of the films combined with low dielectric losses. The effects of the particles were in agreement with the multicore model of Tanaka et al. The particle dispersion was analyzed on SEM images. A correlation between agglomerates and zeta potential in isopropanol was found yielding a quick analysis tool for the tendency of nanoparticles to form clusters during processing with PP. To assure comparability between the films, the real particle content was determined by incineration. The surface roughness of the film has a large influence on the breakdown behavior and was, therefore, also monitored.
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摘要 :
In this work, eleven commercially available nanoparticles are benchmarked against each other according to their potential for an application in a polypropylene (PP) based nanocomposite for thin film power capacitors. Biaxially ori...
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In this work, eleven commercially available nanoparticles are benchmarked against each other according to their potential for an application in a polypropylene (PP) based nanocomposite for thin film power capacitors. Biaxially oriented films containing a fixed concentration of 5 wt%. Al2O3, TiO2, SiO2, or POSS nanoparticles with different surface functionalization were analyzed by dielectric spectroscopy and dielectric breakdown measurements. Two particle systems emerged to increase both the dielectric breakdown strength and the reliability of the films combined with low dielectric losses. The effects of the particles were in agreement with the multicore model of Tanaka et al. The particle dispersion was analyzed on SEM images. A correlation between agglomerates and zeta potential in isopropanol was found yielding a quick analysis tool for the tendency of nanoparticles to form clusters during processing with PP. To assure comparability between the films, the real particle content was determined by incineration. The surface roughness of the film has a large influence on the breakdown behavior and was, therefore, also monitored.
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Ceramic materials based on complex oxides with both the perovskite structure (Ln_(2/3)Nb_2O_6) and the structure of tetragonal tungsten bronze (Ba_(6-x)Ln_(8+2x/3)Ti_(18)O_(54)) have been investigated over a wide frequency and tem...
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Ceramic materials based on complex oxides with both the perovskite structure (Ln_(2/3)Nb_2O_6) and the structure of tetragonal tungsten bronze (Ba_(6-x)Ln_(8+2x/3)Ti_(18)O_(54)) have been investigated over a wide frequency and temperature ranges. The results obtained for certain structures denote the presence of the temperature anomalies of dielectric parameters (ε, tan δ). These anomalies occur over the wide frequency range including submilimeter (SMM) wavelength range, and are related neither with the processing peculiarities nor with the presence of the phase transitions. Temperature behavior of the permittivity has been considered in terms of the polarization mechanism based on the elastic-strain lattice oscillations. It has been assumed that the observed anomalies could be ascribed to a superposition of harmonic and anharmonic contribution to lattice oscillations that determines τ_ε sign and magnitude.
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The high dielectric constant ZrO2, as one of the most promising gate dielectric materials for next generation semiconductor device, is expected to be introduced as a new high k dielectric layer to replace the traditional SiO2 gate...
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The high dielectric constant ZrO2, as one of the most promising gate dielectric materials for next generation semiconductor device, is expected to be introduced as a new high k dielectric layer to replace the traditional SiO2 gate dielectric. The electrical properties of ZrO2 films prepared by various deposition methods and the main methods to improve their electrical properties are introduced, including doping of nonmetal elements, metal doping design of pseudo-binary alloy system, new stacking structure, coupling with organic materials and utilization of crystalline ZrO2 as well as optimization of low-temperature solution process. The applications of ZrO2 and its composite thin film materials in metal oxide semiconductor field effect transistor (MOSFET) and thin film transistors (TFTs) with low power consumption and high performance are prospected.
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In this paper, a complete analysis of the complex dielectric constant of a flexible substrate from the silicon-based polymer- Polydimethylsiloxane (PDMS) is performed, and the obtained results are discussed. Two experimental metho...
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In this paper, a complete analysis of the complex dielectric constant of a flexible substrate from the silicon-based polymer- Polydimethylsiloxane (PDMS) is performed, and the obtained results are discussed. Two experimental methods are applied in this research. The first Two-resonator method is based on resonance measurements by excitation of two types of TE- and TM-mode cylinder resonators with PDMS disks, ensure an accurate determination of the dielectric constant and dielectric loss tangent in both parallel and perpendicular directions (e.g., epsilon par, epsilon(perp)). The second method is based on the tight coverage of planar microstrip ring resonators with non- metalized PDMS samples gives reliable information for the equivalent dielectric parameters (e.g., epsilon(eq), tan delta epsilon(eq)). The obtained results show that PDMS substrates have relatively weak but measurable uniaxial anisotropy and well-expressed frequency dependencies of the extracted dielectric parameters in the range 1-40 GHz, namely epsilon(par) similar to 2.82-2.7; epsilon(perp similar to) 2.73-2.52 and epsilon(eq) similar to 2.75-2.64, tan delta epsilon(eq) similar to 0.017-0.048. The results are confirmed by several other complementary methods. The considered pair of methods are also applied in the temperature interval -40/+70 degrees C; the measured temperature dependencies on the dielectric parameters turn out to be relatively strong. The possible origin of the measured PDMS uniaxial anisotropy has been discussed; in fact, it appears mainly in the temperature range -30/+40 degrees C.
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Polymer-based dielectric materials have potential applications in microelectronics, power electronics, photovoltaics, flexible electronics, MEMS, and sensing industries. The possibility of premature electrical breakdown due to hig...
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Polymer-based dielectric materials have potential applications in microelectronics, power electronics, photovoltaics, flexible electronics, MEMS, and sensing industries. The possibility of premature electrical breakdown due to high electric fields, particularly at high frequencies and in high ambient temperature and humidity conditions, has restricted its widespread adoption. In this paper, we generalize the thermochemical model of dielectric breakdown and establish dielectric heating as the primary ac degradation mechanism in polymers and develop an analytical dielectric breakdown model that satisfactorily explains measured trends in constant and ramp stress tests under both ac and dc electric fields applied to 5- -thick PBO capacitors. We also study and quantify the effects of exposure to ambient relative humidity on the electrical breakdown lifetime of polymer dielectrics. Our study provides a fundamental physical understanding of the frequency, ambient humidity, and thickness dependencies of lifetime and breakdown strength for polymer dielectrics; the proposed breakdown model suggests far more optimistic dielectric lifetimes when accelerated test results are scaled to normal operating conditions.
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Dielectrics and dielectric properties are defined generally and dielectric measurement methods and equipment are described for various frequency ranges from audio frequencies through microwave frequencies. These include impedance ...
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Dielectrics and dielectric properties are defined generally and dielectric measurement methods and equipment are described for various frequency ranges from audio frequencies through microwave frequencies. These include impedance and admittance bridges, resonant frequency, transmission-line, and free-space methods in the frequency domain and time-domain and broadband techniques. Many references are cited describing methods in detail and giving sources of dielectric properties data. Finally a few applications for such data are presented and sources of tabulated and dielectric properties data bases are identified.
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The temperature and frequency dependences of the dielectric constants (ε') and dielectric loss (ε") were studied in glassy Se _(70)Te _(20)Sn _(10) alloy in the audio-frequency range below the glass transition region. The result...
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The temperature and frequency dependences of the dielectric constants (ε') and dielectric loss (ε") were studied in glassy Se _(70)Te _(20)Sn _(10) alloy in the audio-frequency range below the glass transition region. The results indicated that dielectric dispersion occurred in glassy Se _(70)Te _(20)Sn _(10) alloy. Welldefined dielectric peaks were obtained in glassy Se _(70)Te _(20)Sn _(10) alloy; these are rarely observed in chalcogenide glasses. Such loss peaks were not observed in the glassy Se80-xTe20Snx system in the past for Sn concentrations of x ≤ 8. A detailed analysis of the data showed that the results could be explained in terms of dipolar relaxation, with a distribution of relaxation times, This is quite expected in the case of chalcogenide glasses.
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Electromagnetic (EM) inversion is a quantitative imaging technique that can describe the dielectric constant distribution of a target based on the EM signals scattered from it. In this paper, a novel deep neural network (DNN) base...
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Electromagnetic (EM) inversion is a quantitative imaging technique that can describe the dielectric constant distribution of a target based on the EM signals scattered from it. In this paper, a novel deep neural network (DNN) based methodology for ground penetrating radar (GPR) data inversion, known as the ü-net is introduced. The proposed ü-net consists of three parts: a data compression unit, U-net, and an output unit. The novel inversion approach, based on supervised learning, uses a neural network to generate the dielectric constant distribution from GPR data. The GPR data can be compressed and reshaped the size using data compression unit. The U-net maps the object features to the dielectric constant distribution. The output unit meshes the dielectric constant distribution more finely. A novel feature of the proposed methodology is the application of instance normalization (IN) to the DNN EM inversion method and a comparison of its performance to batch normalization (BN). The validity of this technique is confirmed by numerical simulations. The Mean- Square Error of the test data sets is 0.087. These simulations prove that the instance normalization is suitable for GPR data inversion. The proposed approach is promising for achieving quality dielectric constant images in real-time.
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