Computational method of determining dielectric-loss tangent for thin films

1987 ◽  
Vol 30 (10) ◽  
pp. 1011-1013
Author(s):  
E. M. Tolstopyatov
Keyword(s):  
Thin Films ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Computational Method

scholarly journals CONDUCTIVITY AT ALTERNATING CURRENT OF THIN FILMS OF POLYCHLOROPRENE FORMED IN ELECTRIC FIELD

2018 ◽  
Vol 13 (1) ◽  
pp. 75-92 ◽  
Author(s):  
N. N. Komova
Keyword(s):  
Thin Films ◽  
Dielectric Loss ◽  
Electric Field ◽  
Temperature Dependence ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Extreme Values ◽  
Alternating Current ◽  
Limited Region ◽  
Temperature Dependences

The temperature dependences of conductivity at alternating current (a frequency of 1 kHz) were studied for thin polychloroprene films formed from a solution on metal electrodes having different polarities: anode, cathode and zero potential. It was found that the nature and form of the temperature dependence of the conductivity of the investigated polymer film depends on the method of sample formation. Temperature regions of maximum conductivity were detected. The realization of the heating cycle followed by the film cooling in a limited region between the electrodes under the action of an alternating electric field leads to an increase in the specific conductivity and a shift of the extreme values to the region of lower temperatures. This effect is manifested to the greatest extent for films formed at the cathode. The process of heating and subsequent cooling is of hysteresis nature both for permittivity and for the dielectric loss tangent. The dependence of dielectric loss tangent on permittivity in a rather wide temperature range is inversely proportional. During the analysis of temperature dependences the mechanism of conductivity was studied for polychloroprene thin films at direct and alternating current. The determined activation energies of the polymeric system conductivity change enable concluding that the mechanisms of electric conductivity at direct and alternating current are of similar nature. The extreme values of permittivity may be due to structural alterations in the process of heating. This is confirmed by the data on the temperature dependence of dielectric loss tangent. In order to explain conductivity at direct current a model of dipole traps is offered.

scholarly journals Improvement of dielectric loss tangent of Al2O3 doped Ba0.5Sr0.5TiO3 thin films for tunable microwave devices

2004 ◽  
Vol 95 (3) ◽  
pp. 1416-1419 ◽  
Author(s):  
K. B. Chong ◽  
L. B. Kong ◽  
Linfeng Chen ◽  
L. Yan ◽  
C. Y. Tan ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Microwave Devices ◽  
Tunable Microwave

Electrophysical properties of mixtures of mineral oil and synthetic ester dielectric liquid

2021 ◽  
Vol 14 (2) ◽  
pp. 132-141
Author(s):  
M. N. Lyutikova ◽  
S. M. Korobeynikov ◽  
A. A. Konovalov
Keyword(s):  
Dielectric Loss ◽  
Breakdown Voltage ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Kinematic Viscosity ◽  
Mineral Oil ◽  
Flash Point ◽  
Power Transformers ◽  
Synthetic Ester ◽  
Insulating Properties

Power transformers are key equipment in power generation, transmission, and distribution systems. The reliability of power transformers is based on the performance of the insulation system, which includes solid cellulose insulation and a liquid dielectric. Modern power engineering requires liquid insulation to have excellent insulating properties, high fire resistance, and biodegradability. Mineral oil that has been in use for over 100 years does not meet certain requirements. Therefore, various methods of enhancing the insulating properties of the oil are currently being considered, including mixing it with other liquid dielectrics, which have excellent properties. Synthetic and natural esters are considered as alternative fluids.This article discusses the possibility of enhancing the insulating characteristics of mineral oil with a high content of aromatic hydrocarbons (for example, T-750 oil) by mixing it with synthetic ester Midel 7131. Assessment is given of insulating parameters of the resulting mixtures with an ester fraction in mineral oil from 0% to fifty%. The main characteristics of the mixtures are described, such as density, kinematic viscosity, flash point, dielectric loss tangent, relative dielectric permittivity, breakdown voltage, and moisture content. It is shown that with an increase in the proportion of ester, some parameters of the obtained insulating liquid improve (flash point, dielectric constant, breakdown voltage), while values of other parameters (density, kinematic viscosity, dielectric loss tangent) with an ester content of more than 10% in the mixture do not meet the requirements for mineral oils.

Method of calculating the dielectric loss tangent of binary systems

1987 ◽  
Vol 52 (3) ◽  
pp. 310-312
Author(s):  
G. N. Dul'nev ◽  
D. P. Volkov ◽  
M. V. Dobrochasov
Keyword(s):  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Binary Systems

scholarly journals Dielectric and electrical properties of Cr substituted Mg ferrites

2015 ◽  
Vol 39 (1) ◽  
pp. 1-12 ◽  
Author(s):  
AKM Zakaria ◽  
Faizun Nesa ◽  
MA Saeed Khan ◽  
SM Yunus ◽  
NI Khan ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Lattice Parameter ◽  
Activation Energies ◽  
X Ray Diffraction ◽  
Constant E ◽  
Cr Concentration ◽  
Academy Of Sciences

The spinel ferrites MgCrxFe2-xO4 (0.0 ? × ?1.0) were prepared through the solid state reaction using conventional ceramic method at 1300°C in air. The homogeneous phase of the ferrite samples was observed from the X-ray diffraction study. Lattice parameter of the samples was found to decrease with increasing Cr concentration in the system obeying Vegard’s law. The ac electrical resistivity, measured as a function of temperature, decreases with the increase of temperature indicating the semiconducting nature of all the samples. The activation energies were calculated and found to decrease with increasing Cr content. The lower activation energies are associated with higher electrical conductivity. With the increase of temperature, dielectric constant (e`) and dielectric loss tangent are observed to be increased; while with the increase of frequency, dielectric constant (e`) and dielectric loss tangent decrease for all the samples.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 1, 1-12, 2015

Multipurpose Nonwoven Viscose/Polypropylene Fabrics: Effect of Fabric Characteristics and Humidity Conditions on the Volume Electrical Resistivity and Dielectric Loss Tangent

2020 ◽  
Vol 21 (10) ◽  
pp. 2407-2416
Author(s):  
Koviljka A. Asanovic ◽  
Dragana D. Cerovic ◽  
Mirjana M. Kostic ◽  
Tatjana V. Mihailovic ◽  
Aleksandra M. Ivanovska
Keyword(s):  
Electrical Resistivity ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent

scholarly journals In-situ measurement of electric current and dielectric loss tangent during vulcanisation of nitrile rubber.

1998 ◽  
Vol 71 (5) ◽  
pp. 281-285 ◽  
Author(s):  
Toyohiko GONDOH ◽  
Yukiko MATSUOKA ◽  
Michiharu TOH ◽  
Daisaburo OKAI ◽  
Tetsuo MORI
Keyword(s):  
Dielectric Loss ◽  
Electric Current ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Nitrile Rubber ◽  
In Situ Measurement

Dielectric loss tangent of sapphire single crystal produced by edge-defined film-fed growth method

2002 ◽  
Vol 377 (3) ◽  
pp. 313-318 ◽  
Author(s):  
M. Kusunoki ◽  
M. Inadomaru ◽  
S. Ohshima ◽  
K. Aizawa ◽  
M. Mukaida ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Single Crystal ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Growth Method ◽  
Sapphire Single Crystal
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