A Method for Precise Measurement of the Dielectric Constant of Liquids in a Wide Frequency Range

1972 ◽  
Vol 43 (5) ◽  
pp. 763-765 ◽  
Author(s):  
Akira Kakimoto
Keyword(s):  
Dielectric Constant ◽  
Precise Measurement ◽  
Wide Frequency Range ◽  
Frequency Range

DIELECTRIC RELAXATION IN CLAYS SATURATED WITH WATER-OIL EMULSION IN A WIDEBAND OF FREQUENCIES AT POSITIVE AND NEGATIVE TEMPERATURES

2021 ◽  
pp. 96-108
Author(s):  
A. V. Repin
Keyword(s):  
Dielectric Constant ◽  
Wide Frequency Range ◽  
Complex Dielectric Constant ◽  
Relaxation Processes ◽  
Frequency Range ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Negative Temperatures ◽  
Oil Water ◽  
Account Relaxation

The results of measuring the complex dielectric constant of clays saturated with an oil-water emulsion in various ratios in a wide frequency range are presented. The measurements were used out at positive and negative temperatures. It was revealed that several relaxation processes are observed in the spectra. The processes parameters significantly depend on the temperature and the ratio of water and hydrocarbon to the saturating mixture. A model is proposed that makes it possible to take into account relaxation processes and their dependence on temperature.

Solid State Sintering and Microstructural Evolution on Wide Frequency Range Dielectric Responses of Mechanically Activated CaTiO3 Ceramics

2015 ◽  
Vol 1107 ◽  
pp. 38-44
Author(s):  
Wong Yick Jeng ◽  
Hassan Jumiah ◽  
Mansor Hashim
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Microstructural Analysis ◽  
High Energy ◽  
Wide Frequency Range ◽  
Milling Process ◽  
Frequency Range ◽  
Wide Range

The CaTiO3samples were prepared by high-energy ball milling process followed by sintering process from 1040 to 1200°C. X-ray diffraction (XRD), microstructural analysis, and dielectric properties over a wide range of frequency varying from 0.01 Hz to 1 GHz at room temperature were investigated. The formation of a single phase CaTiO3with orthorhombic structure was achieved at 1120°C and above. From a morphological point of view, sintering temperature promoted grain growth. Dielectric properties in the frequency range 0.01 Hz - 1 MHz revealed a relaxation-type process. Interfacial phenomena were the possible physical mechanisms that gave rise to these relaxation-type plots. Extending the frequencies above ~1 MHz yielded a frequency-independent characteristic of dielectric constant (ε'). These turned out to the relatively small dielectric loss (tan δ) values. The origin of the dielectric responses in the frequency range 1 MHz - 1 GHz was attributed to the domination of dipolar polarization. The grain size effect in sintered CaTiO3samples was prominent, notably in dielectric responses above ~1 MHz. Increase in sintering temperature remarkably led to an enhancement in dielectric constant values and reduction in dielectric loss values. Therefore, a significant correlation existed between microstructural features and dielectric properties.

Dielectric Properties of Na2O Doped Cao-B2O3-SiO2 System Glass-Ceramics

2013 ◽  
Vol 750-752 ◽  
pp. 492-496
Author(s):  
Peng Fei Wei
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Glass Ceramics ◽  
Wide Frequency Range ◽  
Microwave Properties ◽  
Low Dielectric Constant ◽  
Frequency Range ◽  
Low Dielectric

The behavior of dielectric and microwave properties against sintering temperature was been carried out on CaO-B2O3-SiO2glass-ceramics with Na2O addition by XRD and SEM. The results show that 0.5 wt.% Na2O addition is advantageous to improve the dielectric and microwave properties due to increasing the major crystalline CaSiO3. With further increasing Na2O content, α-SiO2is the predominant crystalline phase instead of CaSiO3. The CBS glass-ceramics with 0.5 wt.% Na2O sintered at 875°C has a bulk density of 2.51g·cm-3, and which possesses good dielectric properties:εr=6.2,tanδ=1.9×10-3(10 MHz) and low dielectric constant below 2×10-3over a wide frequency range. The proposed dielectrics can find applications in microwave devices, which require low dielectric loss and low dielectric constant.

Dielectric Properties of Graphite Nanosheets Doped Poly(vinylidene Fluoride)/Silicon Carbide Hybrid

2011 ◽  
Vol 279 ◽  
pp. 3-9
Author(s):  
Yu Сhao Li ◽  
Xiang Сai Ge ◽  
Sie Chin Tjong
Keyword(s):  
Silicon Carbide ◽  
Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Wide Frequency Range ◽  
Dielectric Behavior ◽  
Frequency Range ◽  
Molding Process ◽  
Graphite Nanosheets ◽  
Poly Vinylidene Fluoride ◽  
Sic Composites

Binary poly(vinylidene fluoride)/silicon carbide (PVDF/SiC) composites and its graphite nanosheets (GN) doped ternary hybrids were fabricated using simple solution mixing and hot compression molding process. The dielectric behavior of such hybrids was studied over a wide frequency range. Additions of graphite nanosheets with their concentrations close to the percolation threshold were found to be very effective to enhance the dielectric permittivity of PVDF/SiC system. The dielectric constant for PVDF/SiC/GN 80/20/2 system was ~ 200, being twenty times higher than that of neat PVDF. Furthermore, the dielectric behavior of such hybrid displayed strong frequency dependence.

scholarly journals Materials with high dielectric permeability on the basis of spontaneously polarized systems, lithium conductors and transition metal oxides

2021 ◽  
pp. 67-78
Author(s):  
Anatolii G. Belous ◽  
◽  
Oleg I. V'yunov ◽  
Oleg Z. Yanchevskii ◽  
Leonid L. Kovalenko ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
High Dielectric Constant ◽  
Wide Frequency Range ◽  
Dielectric Losses ◽  
Frequency Range ◽  
Dielectric Parameters ◽  
Low Frequencies ◽  
Low Dielectric ◽  
Constant E ◽  
High Dielectric

Materials with a high dielectric constant (e > 1000) based on complex oxides of spontaneously polarized systems, lithium-conducting systems, and oxides of transition metals were studied. It was shown in dielectric ceramics Ba(Ti,Sn)O3 the absence of significant dispersion of dielectric parameters (e and tg δ) in a wide frequency range from 1 to 105 Hz. The introduction of MnO2 and Al2O3-SiO2-TiO2 improves dielectric parameters and reduces sintering temperature. Obtained ceramic materials are characterized by high dielectric constant values e ~ 13000–16000 and low dielectric losses tg d ~ 0.05–0.06 (at 1 MHz). Synthesized solid solutions of La0.5Li0.5-xNaxTiO3 system, where x = 0 and 0.1, have high values e¢ > 104 at low frequencies (f ≤ 10 Hz). Dielectric properties of these materials are determined by the lithium ions mobility that increases with the rise of sodium content by increasing bottleneck size and decreases by the number of lithium vacancies reduction. The disadvantage of such materials is the decrease in dielectric constant with frequency increase. It was found that the ceramic СaСu3Тi4–xAlxО12-y-0.5xFy with x/y = 0.04/0.04 after sintering for 10 h is characterized by dielectric parameters: e¢ » 71000 (1 kHz) and tg d » 0.047. Introduction of aluminum (x/y = 0.04/0) or fluorine (0/0.08) in CCTO reduces dielectric losses (tg d » 0.044). The advantages of this type of material are a wide frequency range of high dielectric constant and relatively low dielectric loss. Synthesized materials can be used for the development of ceramic capacitors with high characteristics.

THE INFLUENCE OF THE SALTITY OF THE MOISTURIZING SOLUTION ON THE DIELECTRIC PERMEABILITY OF CLAYS IN THE FREQUENCY RANGE FROM 1 MHZ TO 8 GHZ

2021 ◽  
pp. 92-101
Author(s):  
A. V. Repin ◽  
O. V. Rodionova
Keyword(s):  
Dielectric Constant ◽  
Salt Solution ◽  
Dielectric Permeability ◽  
Wide Frequency Range ◽  
Complex Dielectric Constant ◽  
Relaxation Processes ◽  
Nacl Solution ◽  
Frequency Range

The article presents the results of measurements of the complex dielectric constant of clays saturated with NaCl solution of various concentrations in a wide frequency range. The measurements were carried out at positive temperatures. It was revealed that several relaxation processes are observed in the spectra. A model is proposed that makes it possible to take into account the relaxation processes and their dependence on the concentration of the salt solution. The concentration practically does not affect the parameters of the processes, in contrast to the temperature.

scholarly journals Lattice strain driven dielectric insulation response of Sr1−xCaxBi2Nb2O9 ceramics

2016 ◽  
Vol 06 (03) ◽  
pp. 1650021
Author(s):  
Vaibhav Shrivastava
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
High Frequency ◽  
Room Temperature ◽  
Lattice Strain ◽  
Calcium Content ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Dielectric Insulation ◽  
Room Temperature Dielectric Constant

In this paper, effects of lattice strain on dielectric properties of Sr[Formula: see text]CaxBi2Nb2O9 ([Formula: see text]–0.5 in steps of 0.1) ceramics are reported. High frequency dipolar polarization is observed to increase for 10% calcium addition and suppresses thereafter on higher calcium concentrations. The dielectric loss values for all doped samples were lower compared to undoped one at frequencies beyond 1[Formula: see text]kHz. The sample with [Formula: see text] shows room temperature dielectric constant in the range (130[Formula: see text][Formula: see text][Formula: see text]12) over a wide frequency range from 50[Formula: see text]Hz to 1[Formula: see text]MHz also minimum dielectric loss among all other sample for the same frequency range. Remarkable increase in Curie temperature ([Formula: see text]) by 50[Formula: see text]C is recorded in the present work by increasing 10% calcium content in SBN compostion. All higher doped samples indicate increase in [Formula: see text] by further higher amount. In addition, dc conductivity of all samples is measured for all samples and increase in calcium content is observed to generate more insulating compositions compared to undoped SBN with higher intrinsic activation energies.

Effect of Sintering Temperatures on Sr-Doped NiO Ceramics

2016 ◽  
Vol 840 ◽  
pp. 61-65 ◽  
Author(s):  
Nurul Nadia Mohd Salim ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Size Range ◽  
Sintering Temperature ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Solid State Method ◽  
State Method

Sr - doped NiO ceramic was prepared using solid state method. The calcination temperature used at 950 oC for 4 hours and the sintering temperatures was varied from 1100 to 1300 oC for 3 hours. The results depict the microstructures increasing in grains size (1-8 μm) by increase of sintering temperatures. The density and porosity testing support the result of microstructures analysis. The larger grains size induced the increase in density and lower in porosity. The dielectric properties is observed in a wide frequency range of (1 - 1 000 MHz). The increase of dielectric constant is associated with the decrease of dielectric loss. The optimum sintering temperature was obtained at 1200 oC depict the grain size range (1 - 2 μm) with highest dielectric constant (1.61 x 103) and lowest dielectric loss (1.15) at 1MHz.

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