Modeling of dielectric relaxation in clays at negative and positive temperatures

2021 ◽  
Vol 64 (1) ◽  
pp. 58-63
Author(s):  
A.V. Repin ◽  
◽  
O.V. Rodionova ◽  
E.S. Kroshka ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Dielectric Constant ◽  
Relaxation Process ◽  
Bound Water ◽  
Complex Dielectric Constant ◽  
Distilled Water ◽  
Frequency Range ◽  
Water Ice ◽  
Free And Bound Water ◽  
The Relationship

Experimental data on measuring the complex dielectric constant (CDP) of clays with full moistening with distilled water in the frequency range from 1 kHz to 8.5 GHz at temperatures from -15 to +25 °C are presented. The modeling of the dependences of is carried out by a multirelaxation model that takes into account the relaxation of free and bound water, as well as relaxation at the bound water - mineral and bound water - air boundaries. It is shown that at temperatures below -5 °C, a relaxation process appears in the CDP spectrum due to polarization at the bound water - ice or ice - mineral interface. The relationship between the parameters of this relaxation process and the petrophysical characteristics of the rock is found.

scholarly journals PENGUKURAN NILAI DIELEKTRIK MATERIAL CALCIUM COPPER TITANAT ( CaCu3Ti4O12) MENGGUNAKAN SPEKTROSKOPI IMPEDANSI TERKOMPUTERISASI

2017 ◽  
Vol 6 (1) ◽  
pp. 26
Author(s):  
Widodo Budi Kurniawan
Keyword(s):  
Dielectric Constant ◽  
Impedance Spectroscopy ◽  
Ceramic Materials ◽  
Complex Dielectric Constant ◽  
Frequency Range ◽  
Frequency Dependent ◽  
Calcium Copper Titanate ◽  
Ccto Sample

Telah dilakukan pengukuran tetapan dielektrik kompleks dan besarnya impedansi kapasitor pada material keramik Calcium Copper Titanate dengan struktur material CaCu3Ti4O12 (CCTO) dengan kemurnian 99 % menggunakan metode spektroskopi impedansi terkomputerisasi dalam rentang frekuensi 5 kHz – 120 kHz. Tetapan dielektrik maksimum terukur pada sampel yang disintering dengan suhu 7000C yaitu 745 pada frekuensi 5 kHz dan besarnya impedansi kapasitor maksimum terjadi pada sampel CCTO non sintering yaitu 150434 Ω. Hasil penelitian menunjukkan adanya pengaruh frekuensi terhadap tetapan dielektrik kompleks dan impedansi kapasitor dari material yang diteliti. Kata kunci : spektroskopi impedansi, CaCu3Ti4O12, tetapan dielektrik kompleks dan impedansi kapasitor.   MEASUREMENT OF THE DIELECTRIC CONSTANT CALCIUM COPPER TITANATE (CaCu3Ti4O12) MATERIALS USING COMPUTERIZED IMPEDANCE SPECTROSCOPY  ABSTRACT The measurement of the complex dielectric constant and the magnitude of the capacitor impedances of the ceramic materials Calcium Copper Titanate CaCu3Ti4O12 (CCTO) with purity of 99% has been done by using the method of computerized impedance spectroscopy in the frequency range 5 kHz - 120 kHz. The highest dielectric constant of the material was found to be 745 at 5 kHz in the sample sintered 7000C and the highest impedance of capacitor occured in CCTO sample non sintered that is 150434Ω. The results showed that complex dielectric constant and impedance of the capacitor of the material under study was frequency dependent. Keywords : impedance spectroscopy, CaCu3Ti4O12,complex dielectric constant and impedance of capacitor

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.

scholarly journals Determination of Relationship between Dielectric Properties, Compressive Strength, and Age of Concrete with Rice Husk Ash Using Planar Coaxial Probe

2016 ◽  
Vol 16 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Nawarat Piladaeng ◽  
Niwat Angkawisittpan ◽  
Sahalaph Homwuttiwong
Keyword(s):  
Dielectric Constant ◽  
Compressive Strength ◽  
Dielectric Properties ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Planar Structure ◽  
Frequency Range ◽  
The Relationship ◽  
Coaxial Probe

Abstract This paper deals with an investigation of the dielectric properties of concretes that includes rice husk ash using a planar coaxial probe. The planar coaxial probe has a planar structure with a microstrip and coaxial features. The measurement was performed over the frequency range of 0.5-3.5 GHz, and concrete specimens with different percentages of rice husk ash were tested. The results indicated that the dielectric constant of the concretes was inversely proportional to the frequency, while the conductivity was proportional to the frequency. The dielectric constant decreased with the increasing age of the concrete at the frequency of 1 GHz. The conductivity of the concrete decreased with the increasing age of the concrete at the frequency of 3.2 GHz. In addition, the dielectric constant and the conductivity decreased when the compressive strength increased. It was also shown that the obtained dielectric properties of the concrete could be used to investigate the relationship between the compressive strength and age of the concrete. Moreover, there is an opportunity to apply the proposed probe to determine the dielectric properties of other materials.

scholarly journals Complex Refractive Index of Strontium Titanate in the Terahertz Frequency Range

2019 ◽  
Vol 7 (4) ◽  
pp. 71-80 ◽  
Author(s):  
V. R. Bilyk ◽  
K. A. Grishunin
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Strontium Titanate ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Complex Dielectric Constant ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Time Domain Spectroscopy ◽  
Terahertz Frequency Range

The recent progress in terahertz time-domain spectroscopy enables the accurate and reliable measurements of dielectric properties in comparison with the traditional far-infrared spectroscopy using an incoherent light source. The broadband THz-TDS is a powerful tool to determine the real and imaginary parts of a complex dielectric constant by the transmission which allows to detect the parameters of the soft modes in ferroelectrics. In this work, the terahertz time-domain spectroscopy was used to investigate the dependence of the complex refractive index of a single-crystal quantum paraelectric strontium titanate in the terahertz frequency range from 0.3 to 2 THz. It was shown that the low-frequency terahertz response of the material is determined by the soft phonon mode TO1. The measured experimental dependences showed a good agreement with the theoretical curves obtained from the analysis of the Lorentz oscillator model for the complex dielectric constant of strontium titanate. The obtained results are necessary for understanding the principle of possibility to manipulate the order parameter in ferroelectric materials and can be used to create energy-efficient memory devices with a speed of recording information close to the theoretical limit.

THE COMPLEX DIELECTRIC CONSTANT AT LOW MICROWAVE FREQUENCIES OF ETHYL CHLORIDE ADSORBED ON POROUS VYCOR GLASS

1961 ◽  
Vol 39 (3) ◽  
pp. 425-442 ◽  
Author(s):  
J. D. McCowan ◽  
R. McIntosh
Keyword(s):  
Dielectric Constant ◽  
Coaxial Line ◽  
Ethyl Chloride ◽  
Complex Dielectric Constant ◽  
Frequency Range ◽  
Vycor Glass ◽  
Microwave Frequencies ◽  
The Real ◽  
Porous Vycor Glass ◽  
Accuracy Of Measurement

The complex dielectric constant of the system Vycor glass – ethyl chloride has been measured at three temperatures in the range +11 °C to −33 °C and in the frequency range between 500 Mc sec−1 and 4000 Mc sec−1 by the use of a coaxial line. The real and imaginary parts of the dielectric constant of the adsorbate have also been evaluated. Appreciable loss in the adsorbed matter is found for small quantities adsorbed, and loss is again detected at the highest frequencies and lowest temperatures for the matter held in multilayers or condensed in capillaries. The frequency range and accuracy of measurement were not sufficient to classify the type of loss curve, but other evidence suggests that the loss for the first quantities adsorbed will turn out to be that for rotational oscillators. In general earlier observations of this system are confirmed and extended.

Influence of Structural Parameters of Conducting Polymers on their Microwave Properties

1993 ◽  
Vol 328 ◽  
Author(s):  
P. Hourquebie
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Conducting Polymers ◽  
Molar Mass ◽  
Alkyl Chain ◽  
Structural Parameters ◽  
Microwave Properties ◽  
Complex Dielectric Constant ◽  
Frequency Range ◽  
Counter Anion

ABSTRACTThe complex dielectric constant ε* (ε* = ε′-iε″) of conducting polymers (polyaniline and poly (3-alkyl thiophene)) is studied over a frequency range spanning from 130 MHz to 20 GHz. The effects of structural parameters (counter-anion size, Molar Mass, length of the alkyl chain on the substituted Monomer) on electrical properties (σdc and ε* values) have been investigated.

scholarly journals Влияние химического состава кристаллов TlIn-=SUB=-1-x-=/SUB=-Er-=SUB=-x-=/SUB=-S-=SUB=-2-=/SUB=- (0≤ x≤0.01) на их диэлектрические характеристики и параметры локализованных состояний

2019 ◽  
Vol 61 (11) ◽  
pp. 2030
Author(s):  
С.Н. Мустафаева ◽  
М.М. Асадов
Keyword(s):  
Dielectric Constant ◽  
Charge Transfer ◽  
Chemical Composition ◽  
High Frequency ◽  
Ac Conductivity ◽  
Relaxation Dispersion ◽  
Complex Dielectric Constant ◽  
High Frequency Range ◽  
Frequency Range ◽  
Frequency Dependences

The frequency dependences of the real (ε) and imaginary (ε ″) components of the complex dielectric constant, tangent of dielectric loss (tan) and ac conductivity (σac) of the obtained TlIn1-хErхS2 (0  x  0.01) crystals have been studied in the frequency range f = 5104–3.5107 Hz. It is established that in TlIn1-хErхS2 a relaxation dispersion of ε and ε″ takes place. The effect of erbium concentration (Er) in TlIn1-хErхS2 crystals on their dielectric coefficients was studied. In the high frequency range, the ac conductivity of TlIn1-хErхS2 crystals obeyed the σac ~ f 0.8 law, which is characteristic of a hopping charge transfer mechanism at states localized near the Fermi level. The parameters of states localized in the band gap and the influence of the chemical composition of the TlIn1-хErхS2 crystals on these parameters are estimated.

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.

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