scholarly journals Investigation of dielectric properties of heterostructures based on ZnO structures

2018 ◽  
Vol 35 (4) ◽  
pp. 885-892
Author(s):  
A.H. Selçuk ◽  
E. Orhan ◽  
S. Bilge Ocak ◽  
A.B. Selçuk ◽  
U. Gökmen
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Frequency Dependence ◽  
Loss Tangent ◽  
Electrical Modulus ◽  
Ac Electrical Conductivity

Abstract The voltage and frequency dependence of dielectric constant є′, dielectric loss є″, electrical modulus M″, M′, loss tangent tanδ and AC electrical conductivity σAC of p-Si/ZnO/PMMA/Al, p-Si/ZnO/Al and p-Si/PMMA/Al structures have been investigated by means of experimental G-V and C-V measurements at 30 kHz, 100kHz, 500 kHz and 1 MHz in this work. While the values of є′, є″, tanδ and σAC decreased, the values of M′ and M″ increased for these structures when frequency was increased and those of p-Si/ZnO/Al and p-Si/PMMA/Al were comparable with those of p-Si/ZnO/PMMA/Al. The obtained results showed that the values of p-Si/ZnO/PMMA/Al structure were lower than the values of p-Si/ZnO/Al and p-Si/PMMA/Al.

scholarly journals Fabrication and studying the dielectric properties of (polystyrene-copper oxide) nanocomposites for piezoelectric application

2019 ◽  
Vol 8 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Dalal Hassan ◽  
Ahmed Hashim Ah-yasari
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Copper Oxide ◽  
Electrical Resistance ◽  
Copper Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Increase With Increase

The preparation of (polystyrene-copper oxide) nanocomposites have been investigated for piezoelectric application. The copper oxide nanoparticles were added to polystyrene by different concentrations are (0, 4, 8 and 12) wt.%. The structural and A.C electrical properties of (PS-CuO) nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of (PS-CuO) nanocomposites decrease with increase in frequency. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of polystyrene increase with increase in copper oxide nanoparticles concentrations. The results of piezoelectric application showed that the electrical resistance of (PS-CuO) nanocomposites decreases with increase in pressure.

scholarly journals Dielectric properties of zinc sulfide concentrate during the roasting at microwave frequencies

2017 ◽  
Author(s):  
Guangjun He ◽  
Shiwei Li ◽  
Kun Yang ◽  
Jian Liu ◽  
Peng Liu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Zinc Sulfide ◽  
Apparent Density ◽  
Loss Tangent ◽  
Loss Factor ◽  
Microwave Energy ◽  
Dielectric Loss Factor ◽  
Sulfide Concentrate

Microwave technology has a potential application in the extraction of zinc from sulphide ores, knowledge of the dielectric properties of these ores plays a major role in the microwave design and simulation for any process. The dielectric properties of zinc sulfide concentrate for two different apparent densities—1.54 and 1.63 g/cm3—have been measured by using the resonance cavity perturbation technique at 915 and 2450 MHz during the roasting process for the temperature ranging from room temperature to 850 °C. The variations of dielectric constant, the dielectric loss factor, the dielectric loss tangent and the penetration depth with the temperature, frequency and apparent density have been investigated numerically. The results indicate that the dielectric constant increases as the temperature increases and temperature has a pivotal effect on the dielectric constant, while the dielectric loss factor has a complicated change and all of the temperature, frequency and apparent density have a significant impact to dielectric loss factor. Zinc sulfide concentrate is high loss material from 450 to 800 °C on the basis of theoretical analyses of dielectric loss tangent and penetration depth, its ability of absorbing microwave energy would be enhanced by increasing the apparent density as well. The experimental results also have proved that zinc sulfide concentrate is easy to be heated by microwave energy from 450 to 800 °C. In addition, the experimental date of dielectric constant and loss factor can be fitted perfectly by Boltzmann model and Gauss model, respectively.

AC CONDUCTIVITY AND DIELECTRIC PROPERTIES OF MANGANESE DOPED LAYERED Na1.89Li0.10K0.01Ti3O7 CERAMICS

2013 ◽  
Vol 28 (01) ◽  
pp. 1350200
Author(s):  
SHRIPAL SHARMA ◽  
RAKESH SINGH ◽  
GEETIKA
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Properties ◽  
Chemical Synthesis ◽  
Loss Tangent ◽  
Relative Permittivity ◽  
Ac Electrical Conductivity ◽  
Conduction Mechanisms ◽  
Tan Δ ◽  
Electron Clouds ◽  
Derivatives Of

Manganese doped derivatives of polycrystalline Na 1.89 Li 0.10 K 0.01 Ti 3 O 7 bearing 0.01, 0.05 and 1.0 molar % of manganese have been prepared by chemical synthesis. The results of ac electrical conductivity studies in form of log (σT) versus 1000/T plots are reported in the frequency and temperature range of 10 kHz–1 MHz and 350–775 K, respectively. The corresponding plots have been divided into five temperature regions, I, II, III, IV and V. The various conduction mechanisms in different regions have been discussed. The nature of conductivity has been explained by proposing a model about the obtained conductivity σ(ω) which is the sum of three terms arising from three different mechanisms. Moreover, various Na–K–Li–O–Ti–O linkages in Na 2-x-y Li x K y Ti 3 O 7 materials may result special forms of electron clouds. Experimental results of the loss tangent ( tan δ) and relative permittivity (εr) versus temperature at different frequencies have been described. The results of tan δ and εr versus frequency plots at different temperature have also been given for these doped derivatives.

MEASUREMENT OF THE DIELECTRIC PROPERTIES OF LOW LOSS MATERIALS AT MILLIMETER WAVELENGTHS

1958 ◽  
Vol 36 (12) ◽  
pp. 1672-1677
Author(s):  
A. G. Mungall
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Brewster Angle ◽  
Angle Of Incidence ◽  
Low Loss ◽  
Millimeter Wavelengths ◽  
Space Technique

Measurement at millimeter wavelengths of the dielectric properties of low loss materials by a free space technique is described. The dielectric constant is determined from the Brewster angle, and the dielectric loss tangent from the attenuation coefficient measured at the Brewster angle of incidence. Results are given for bakelite at wavelengths between 5 and 10 mm. Details of the instrument, which was specifically designed for these measurements, are also given.

Surface Morphology and Dielectric Properties of KNN/PI Films

2014 ◽  
Vol 1015 ◽  
pp. 240-243
Author(s):  
Jia Qi Lin ◽  
Hui Lin ◽  
Ying Liu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Surface Morphology ◽  
Loss Tangent ◽  
Mass Fraction ◽  
Dispersion Polymerization ◽  
Polymerization Process ◽  
Insulating Properties

Polyimide (PI) films filled with K0.5Na0.5NbO3 particles at different weight 0wt%,5wt%,10wt%,15wt% and 20wt% had been prepared by in-situ dispersion polymerization process in this article. then we measured morphology and dielectric properties. when the mass fraction of KNN reach 20%, its dielectric constant achieve 4.9(100Hz) with the dielectric loss tangent value is less than 0.025 (100 Hz).it Shows the good insulating properties.

scholarly journals Investigation of the dielectric properties of copolymers based on 2,3,4,5,6-pentafluorostyrene, styrene, 4-fluoro-α-methylstyrene and α-methylstyrene

2019 ◽  
Vol 60 (12) ◽  
pp. 87-90
Author(s):  
Ignat S. Dolgin ◽  
◽  
Pyotr P. Purygin ◽  
Yury P. Zarubin ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Signal Generator ◽  
Frequency Signal ◽  
Current Frequency ◽  
Dielectric Characteristics ◽  
Methyl Styrene

Three new copolymers based on fluorine-containing derivatives of styrene and α-methylstyrene were obtained. According to the results of the previous stages of the study, copolymers based on styrene derivatives have improved dielectric properties compared to polystyrene and a copolymer of styrene and α-methyl styrene. The dielectric constant ε and dielectric loss tangent tanδ were measured for the initial and synthesized samples of styrene – α-methyl styrene copolymer at Samara Electromechanical Plant OJ-SC (Samara city, Russia). All measurements of dielectric characteristics were carried out at an alternating current frequency of 10 GHz on a pressed copolymer tablet with a diameter of 10 and a thickness of 3 mm. During the experiment, a measuring stand was used, consisting of a high-frequency signal generator G4-83, an electronically counting frequency meter Ch3-54 with a frequency converter YaZCh-43, a measuring amplifier U2-4; low-frequency signal generator G3-109; measuring unit FKDG 418151.002. The results obtained indicate high values of the dielectric constant. For samples of copolymers of α-methylstyrene – 4-fluoro-α-methylstyrene and styrene – 4-fluoro-α-methylstyrene, values of 4.63 and 4.21, respectively, were obtained. These dielectric permittivity values are superior not only to samples previously obtained during the experiment, but also to some other compounds that are widely used in industry. In particular, the dielectric constant of lavsan, which is used in the manufacture of capacitors, is 3.1-3.3. The improved dielectric constant values are probably related to the high-quality composition of the copolymer. Samples of the copolymer containing 4-fluoro-α-methylstyrene are significantly superior to the copolymer with 2,3,4,5,6-pentafluorostyrene for this characteristic. The values of the dielectric loss tangent are in the range from 8.74∙10−4 to 37.4∙10−4. Given the dielectric characteristics of the synthesized copolymers, we can conclude that there are good prospects for the use of fluorine-containing styrene copolymers. The obtained values of permittivity and dielectric loss tangent indicate a good possible competitiveness of new materials based on new copolymers. In the future, it is planned to study a number of other physicochemical properties of these materials in order to obtain the most complete spectrum of their characteristics.

Frequency dependence of dielectric characteristics of seawater ionic solution under static magnetic field

2017 ◽  
Vol 31 (23) ◽  
pp. 1750169
Author(s):  
Shaoshuai Guo ◽  
Yufeng Peng ◽  
Xueyun Han ◽  
Jiangting Li
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Frequency Dependence ◽  
Static Magnetic Field ◽  
Complex Permittivity ◽  
Electrolyte Solutions ◽  
Nacl Solution ◽  
Ionic Solution

In order to study the electromagnetic wave transmission characteristics in seawater under external physical effects, we present a study of seawater ionic solution and perform a theoretical basis of magnetic field on water molecules and ionic motion to investigate the variation of dielectric properties with frequency under static magnetic field (0.38 T). Seawater is a naturally multi-component electrolyte solution, the main ingredients in seawater are inorganic salts, such as NaCl, MgSO4, MgCl2, CaCl2, KCl, NaHCO3, etc. The dielectric properties of these electrolyte solutions with different salinity values (0.01–5%) were measured in frequencies ranging from 40 to 5 MHz at 12[Formula: see text]C. The results show that the dielectric constant decreases with increasing frequencies no matter with magnetic field or without it. Frequency dependence of the dielectric constant of NaCl solution increases under magnetic field at measure concentrations. In a solution of MgCl2 ⋅ 6H2O, KCl and NaHCO3 are consistent with NaCl solution, while CaCl2 ⋅ 2H2O solution is in contrast with it. We also find that dielectric loss plays a major role in complex permittivity. With the effect of magnetic field, the proportion of dielectric loss is reducing in complex permittivity. On this basis it was concluded that the magnetic field influences the orientation of dipoles and the variation is different in salt aqueous solution.

DIELECTRIC PROPERTIES OF Li-Sb FERRITES

2005 ◽  
Vol 19 (18) ◽  
pp. 899-905 ◽  
Author(s):  
SHIVAJI CHONGTHAM ◽  
SUMITRA PHANJOUBAM ◽  
H. N. K. SARMA ◽  
RADHAPIYARI LAISHRAM ◽  
CHANDRA PRAKASH
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Room Temperature ◽  
Substitution Level ◽  
Higher Temperature ◽  
Tan Δ ◽  
Almost All ◽  
Frequency Curves

Dielectric properties such as dielectric constant (ε′) and dielectric loss tangent ( tan δ) of Li 0.5+x Fe 2.5-2x Sb x O 4 ferrites, 0.10≤ x ≤0.30 in steps of 0.05 have been investigated as a function of composition, frequency and temperature. The dielectric constant showed dispersion with frequency in the range of 100 Hz–1 MHz. Peaks were observed in the tan δ versus frequency curves for almost all the samples. The temperature variation of dielectric constant for the different samples was studied at 10 kHz in the temperature range from room temperature to 433 K. Peaks were observed for some of the samples. The peaks were seen to shift towards higher temperature region as the substitution level increases. The mechanisms involved in the processes are discussed in this paper.

scholarly journals Studying the Effect of Titania Additions on some properties of Porcelain

2018 ◽  
Vol 28 (2) ◽  
pp. 169
Author(s):  
Abbas K. Saadon
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Titanium Oxide ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manufacturing Method

The paper presents the production of porcelain for the ceramic by inexpensive natural raw materi-als, the principal raw materials of porcelain composition was selected consisting of 50% kaolin, 25% feldspar, 25% silica, the sample synthesized were characterize by X-ray diffraction (XRD) technique, than study the effect additives at different concentration form titanium oxide (𝑇𝑖𝑂2 )at (2, 5, 10, 15, 20) wt% on some physical and dielectric properties of porcelain. The samples are prepared by the conventional manufacturing method. The physical and dielectric properties of porcelain show that change considerably with the sub-stituent sample. It was found that the increase of the titanium oxide (𝑇𝑖𝑂2 ) additives of all our sample produce increasing in dielectric constant and bulk density, while decreasing with open porosity and dielectric loss tangent.

Structural, Electrical and Dielectric Properties of Nanocrystalline Mg-Zn Ferrites

2012 ◽  
Vol 510-511 ◽  
pp. 51-57 ◽  
Author(s):  
M. Anis-ur-Rehman ◽  
M.A. Malik ◽  
S. Nasir ◽  
M. Mubeen ◽  
K. Khan ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Crystallite Size ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Sol Gel ◽  
Phenomenological Theory ◽  
Ac Electrical Conductivity ◽  
Electrical And Dielectric Properties ◽  
Scherrer Formula

The nanocrystalline Mg-Zn ferrites having general formula Mg1-xZnxFe2O4(x=0, 0.1, 0.2, 0.3, 0.4, 0. 5) were prepared by WOWS sol-gel route. All prepared samples were sintered at 700°C for 2 h. X-ray powder diffraction (XRD) technique was used to investigate structural properties of the samples. The crystal structure was found to be spinel. The crystallite size, lattice parameters and porosity of samples were calculated by XRD data analysis as function of zinc concentration. The crystallite size for each sample was calculated using the Scherrer formula considering the most intense (3 1 1) peak and the range obtained was 34-68 nm. The dielectric constant (ε), dielectric loss tangent () and AC electrical conductivity of nanocrystalline Mg-Zn ferrites are investigated as a function of frequency. The dielectric constant (ε), dielectric loss tangent () increased with increase of Zn concentration. All the electrical properties are explained in accordance with MaxwellWagner model and Koops phenomenological theory.

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