Dielectric phase

In both of the latter cases, the appearance of a triple point, CP, of coexistence is characteristic—in the second case, of two metallic and one dielectric phase, and in the third of a metal and two dielectric (liquid and gaseous) phases. 

Dielectric loss tangent The difference between 90° and the dielectric phase angle for a material. 

Considerable interest also has been directed at the use of multicomponent composites where, in theory, the most useful properties from each phase can be realized in the whole. This includes metallodielectric structures where a metallic phase imparts, for example, a high index or more exotic effect (e.g., plasmon resonance) and a low-loss or property-tunable dielectric phase. The dielectric phase can be ceramic or polymeric and also has included ferroelectric polymers, embedded nanoparticles, and organic/inorganic hybrids. ... 

Figure 2. Real p (curves 1) and imaginary p" (curves 2) parts of complex permeability for /= 25 MHz vs metallic-to-dielectric phases ratio x in the nanocomposiles of set 2 deposited in argon-nitrogen gas mixture with p = 1.31 10 Pa (a) and p = 2.13-10 Pa (b).

When a dielectric phase (solid or fluid) is placed in contact with polar hquid, such as water, the interface becomes charged due to either specific adsorption of ions initially dissolved in the polar liquid, or dissociation of surface ionizable groups. - The final result of these two processes is the formation of an electric double layer (EDL) (Figure 5.67), which may contain three types of ions ... 

Another consequence of Wigner crystal creation in dielectric phase is the appearance of lattice distortion becau-... 

Gouy-Chapman Theory A description of the electric double layer in a colloidal dispersion in which one layer of charge is assumed to exist as a uniform charge distribution over a surface and the counterions are treated as point charges distributed throughout the continuous dielectric phase. 

In this treatment we shall allow variation of the entropy, volume, and mass of components in the dielectric phase only. Use of Eqs. (14-4), (14-5), (14-6), and (14-10) yields... 

The structure changes of metallic (5, 5) carbon nanotube at its expansion are calculated by the molecular orbital method. It is found that the ground state of the non-expanded nanotube is dielectric (phase A) as a result of Peierls distortions. The phase A has the Kekule structure with a triple translation period in comparison with the metallic phase (phase C). Two structural first order phase transitions are revealed. The transition between the phase A and intermediate phase B takes place at the elongation of 5 %. The transition between the phases B and C takes place at the elongation of 13 %. The metastable states are found for the phases A and B. 

Los] Loseva, G.V., Sokolovich, V.V., Petukhov, E.P., Baranov, A.V., Metal-Dielectric Phase Transition in Chromium-Iron Thiospinel (in Russian), Fiz. Tverd. Tela, 21(7), 2125-2197 (1977) (Experimental, Crys. Sfructure, Electr. Prop., Magn. Prop., 2)... 

Fig. 6. Capacitor equivalent circuit with real dielectric phase vectors a) parallel circuit, b) serial circuit.

These experimental findings for low-frequency electromagnetic response are in contrast with the expectations for the Anderson IMT [99] in which electronic behavior is controlled by disorder. In the dielectric phase, electrons are bound by fluctuations of the random potential. On the metallic side of the transition, free carriers have short scattering times. In the metallic phase near the transition s is positive because the disorder causes dynamic polarization due to slowing diffusion due to localization effects. When approaching the IMT transition the localization effects increase and s diverges (dielectric catastrophe [120]). 

Dielectric phase angle n. The angular difference in phase between the alternating voltage (usually sinusoidal) applied to a dielectric and the resulting current. The angle is often symbolized by 9, the cosine of which is the power factor. Ku CC, Liepins R (1987) Electrical properties of polymers. Hanser Publishers, New York. 

In particular, Alberti et al. (1991) proposed zeolite-based sensors for detection of hydrocarbons such as butane and Balkus et al. (1997) used thin film aluminophosphate (AlPO)-5 molecular sieve as the dielectric phase in a capacitance-type chemical sensor for CO and CO. AlPO-n is a family of phosphorus molecular sieves which, similar to zeolites, have ordered molecular-sized pores. The AlPO-5 structure used for the dielectric layer consists of four- and six-membered rings of alternating phosphate and aluminum ions bridged by oxygen. These rings are arranged to produce one-dimensional channels 0.73 nm in diameter. The properties of AlPO-n are reviewed in detail by Ishihara and Takita (1996), and one of the attractive properties of these materials is their heat stability. The properties of zeolites as they relate to zeolite-based gas sensors are discussed in a special section in Vol. 2. 

DIELECTRIC POWER FACTOR The cosine of the dielectric phase angle (or sine of the dielectric loss angle). 

Dielectric Loss Angle. (Dielectric Phase Difference) The difference between 90 deg and the dielectric phase angle. 

---