Dielectric Constant

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dielectric constant

[‚dī·ə′lek·trik ′kän·stənt]
(electricity)
For an isotropic medium, the ratio of the capacitance of a capacitor filled with a given dielectric to that of the same capacitor having only a vacuum as dielectric.
More generally, 1 + γχ, where γ is 4π in Gaussian and cgs electrostatic units or 1 in rationalized mks units, and χ is the electric susceptibility tensor. Also known as relative dielectric constant; relative permittivity; specific inductive capacity (SIC).
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Dielectric Constant

a quantity that characterizes the dielectric properties of a medium—its reaction to an electrical field. In the relation D = ∊E, where E is the field strength and D is the electrical induction in the medium, the dielectric constant is the proportionality factor ∊. For most dielectrics, the dielectric constant in fields that are not very strong is not a function of the field E. In strong fields (comparable to intra-atomic fields), and for certain dielectrics (such as ferroelectric materials) in ordinary fields, the relationship between D and E is nonlinear.

The value of the dielectric constant depends essentially on the type of substance and on the external conditions (temperature, pressure, and so on). In alternating electrical fields the dielectric constant is a function of the frequency of the field E.

References in periodicals archive ?
Additionally, the dielectric constant ([epsilon]'), the dielectric loss factor ([epsilon]"), and the conductivity ([sigma]) values were calculated at 1 kHz and at the room temperature.
The piezoelectric deformation is proportional to the square of the polarization, and the polarization is proportional to the dielectric constant. Therefore, piezoelectric performance can be estimated by a dielectric constant measurement, as more deformation energy would be induced by a larger dielectric constant.
Figure 13 depicts the concentration dependence of bulk dielectric constant and DC conductivity.
Dielectric constant and tangent loss showed normal dispersion behavior.
The high dielectric constant and energy storage density of the P(VDF-TrFE)/P(VDF-TrFE-CFE) blend system can be used for practical application in flexible field-effect transistor (FET), nanogenerators and ferroelectric random access memory (FeRAM) like devices."
Such type of morphology is important to lower dielectric constant, as they can hold a lot of air voids between them.
Figure 5 shows the dielectric constant, as a function of the weight fraction of CCTO in the composites, for 2.7 GHz and 5.0 GHz cavities, measured at room temperature.
The dielectric constant and dielectric loss of the azo polymers and the precursor were measured in the frequency range of 100 Hz-200 kHz.
As porosity increases, the alloy's dielectric constant decreases but the mechanical and electrical properties degrade [8, 9].
The decrease in dielectric constant is imputed to the reduction in the internal viscosity of the substituted samples.
In a recently published article in the journal Materials Horizons, Baratunde Cola, an associate professor in the Woodruff School of Mechanical Engineering at the Georgia Institute of Technology, highlights the potential of silicon dioxide nanoparticles coated with a high dielectric constant polymer for cooling power-hungry electronic devices.
Changes in this electromagnetic field are directly proportional to the dielectric constant of the material through which it passes.

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