Relative permittivity constant

In the case when there is no preferred orientation, that is = 0, the considered system is isotropic and is characterised by the relative permittivity constant... 

The dielectric constant (permittivity) tabulated is the relative dielectric constant, which is the ratio of the actual electric displacement to the electric field strength when an external field is applied to the substance, which is the ratio of the actual dielectric constant to the dielectric constant of a vacuum. The table gives the static dielectric constant e, measured in static fields or at relatively low frequencies where no relaxation effects occur. 

Dielectric constant (specific inductive capacity, relative permittivity) over a wide range of temperature and frequency. 

The influence of a particular dielectric on the capacitance of a condenser is conveniently assessed by the dielectric constant, also known as the relative permittivity or rarely specific inductive capacity. This is defined as the ratio of the relative condenser capacity, using the given material as a dielectric, to the capacity of the same condenser, without dielectric, in a vacuum (or for all practical intents and purposes, air). 

Relative Permittivity lEC 250. The term relative permittivity is currently more commonly used than the term dielectric constant used by the author and most of the references quoted in this chapter. As explained in this chapter, it is a ratio and thus dimensionless. 

It can be shown that the electric susceptibility is related to the relative permittivity or dielectric constant e of the particle by the relationship [88]... 

The insulating property of any insulator will break down in a sufficiently strong electric field. The dielectric strength is defined as the electric strength (V/m) which an insulating material can withstand. For plastics the dielectric strength can vary from 1 to 1000 MV/m. Materials may be compared on the basis of their relative permittivity (or dielectric constant). This is the ratio of the permittivity of the material to the permittivity of a vacuum. The ability of a... 

An interface between two immiscible electrolyte solutions (ITIES) is formed between two liqnid solvents of a low mutual miscibility (typically, <1% by weight), each containing an electrolyte. One of these solvents is usually water and the other one is a polar organic solvent of a moderate or high relative dielectric constant (permittivity). The latter requirement is a condition for at least partial dissociation of dissolved electrolyte(s) into ions, which thus can ensure the electric conductivity of the liquid phase. A list of the solvents commonly used in electrochemical measurements at ITIES is given in Table 32.1. 

The uncharged ion is transferred into a solvent with permittivity e = De0y where D is the relative permittivity (dielectric constant) of the medium. No work is gained or lost in this process. In the solvent, the ion is again recharged to the value of the electric potential at its surface,... 

To begin with, molecular solvents with high permittivities will be considered. Classification of solvents on the basis of their permittivities agrees roughly with classification as polar and non-polar, and the borderline between these two categories is usually considered to be a relative dielectric constant of 30-40. Below this value ion pairs are markedly formed. From... 

Another important group of oxide materials with a very low electrical conductivity is the oxide dielectrics. A number of these are based upon the perovskites, MXO3 or M0 X02. The archetype of these materials is BaTiC>3, which has a high dielectric constant, or relative permittivity to vacuum, the value at room temperature being 1600, and commercial use is made of the isostructural PbTi(>3 and ZrTi03 which form solid solutions, the PZT dielectrics. These materials lose their dielectric properties as the temperature... 

The first (exponential) term represents repulsion between electron orbitals on the atoms. The second term can be seen to be opposite in sign to the first and so represents an attraction—the weak van der Waals interaction between the electron orbitals on approaching atoms. The adjustable parameters can sometimes be calculated using quantum mechanics, but in other systems they are derived empirically by comparing the measured physical properties of a crystal, relative permittivity, elastic constants, and so on, with those calculated with varying parameters until the best fit is obtained. Some parameters obtained in this way, relevant to the calculation of the stability of phases in the system SrO-SrTiC>3, are given in Table 2.3. 

Dielectric constant (or relative permittivity), er, is an indication of the polarity of a solvent, and is measured by applying an electric field across the solvent between... 

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