Frequency and Temperature Effects on Dielectric Properties of PEDOT-VC Copolymer

The copolymer based on Poly(3, 4-Ethylene dioxythiophen) and Poly(n-Vinylcarbazole) was characterized by FTIR and Raman spectroscopy. The temperature and frequency evolutions of dielectric parameters are also plotted and studied. The dependence of ε” on the temperature shows relaxation process for studied copolymer especially with frequencies about 1kHz for the temperatures: 90°C < T < 118°C. The values of ε’∞, ε’’MAX, relaxation time and DC conductivity corresponding to the copolymer are also determined with the aim to provide dielectric analysis involving vital information about this new polymeric compound.

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Microwave Dielectric Measurements of 4-Nitroacetanilide at Different Temperatures in Carbon Tetrachloride Solution

Oriental Journal Of Chemistry ◽

10.13005/ojc/340658 ◽

2018 ◽

Vol 34 (6) ◽

pp. 3123-3128

Author(s):

Chitra Manro ◽

Ritu Jain

Keyword(s):

Relaxation Time ◽

Carbon Tetrachloride ◽

Relaxation Process ◽

Activation Parameters ◽

Flow Process ◽

Dielectric Parameters ◽

Microwave Dielectric ◽

Different Temperatures ◽

Intramolecular Rotation ◽

Probable Relaxation Time

The dielectric properties of 4-Nitroacetanilide have been discussed at four different temperatures in the dilute solution of carbon tetrachloride at a fixed frequency of 9.27GHz. The values of dielectric constant (εʹ), dielectric loss (εʺ), permittivity at an optical frequency (ε∞) and permittivity at a static frequency (ε0) are measured at different temperatures and mole fractions. The values of these dielectric parameters are used to calculate the values of relaxation time for overall molecular rotation (τ1), relaxation time for intramolecular rotation (τ2), most probable relaxation time (τ0) and dipole moment (μ) at different temperatures. In the present investigation we have found higher values of τ2 which indicate the existence of more than one relaxation process in the solution. The values of energy activation parameters for dielectric relaxation process (∆Fε, ∆Hε and ∆Sε) and viscous flow process (∆Fη, ∆Hη and ∆Sη) are also determined and compared for 4-Nitroacetanilide with carbon tetrachloride at different temperatures. It is observed that we may treat both the process as a rate process.

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Influence of Ca-Doping on Structural, Magnetic and Dielectric Properties of Ba3Co2-xCaxFe24O41 Hexaferrite Powders

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.241.226 ◽

2015 ◽

Vol 241 ◽

pp. 226-236 ◽

Cited By ~ 3

Author(s):

Neha Solanki ◽

Rajshree B. Jotania

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Sol Gel ◽

Calcium Content ◽

Combustion Method ◽

Dielectric Behavior ◽

Dielectric Parameters ◽

Ca Doping ◽

Auto Combustion ◽

Magnetic And Dielectric Properties

Influence of Ca substitution on structural, magnetic and dielectric properties of Ba3Co2-xCaxFe24O41(where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), prepared by Sol-Gel auto-combustion method, has been investigated in present studies. The obtained powder was sintered at 950 oC for 4 hrs. in the static air atmosphere. Structural analysis of Ca-doped Ba3Co2-xCaxFe24O41powders revealed pure Z-type hexaferrite phase at low temperature. The frequency dependent dielectric constant (Єʹ) and magnetic properties such as remanent magnetization (Mr), saturation magnetization (Ms) and coercivity (Hc) were studied. It is observed that coercivity increased gradually with increase in calcium content. The real dielectric constant (Єʹ) and dielectric loss tangent (tan δ) were studied in the frequency range of 20Hz to 2MHz. The dielectric parameters for all samples show normal dielectric behavior as observed in hexaferrites. Contents of Paper

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