Theory Of Dielectric Dispersion Research Articles

On the Dielectric Study of Se80−x Te20Pb x (x = 0, 1 and 2) Glasses

In the present paper, the dielectric parameters such as the dielectric constant e′(ω), dielectric loss e″(ω) and alternating current (ac) conductivity have been investigated for bulk amorphous chalcogenide Se80−xTe20Pbx (x = 0, 1 and 2) glasses in the frequency range 10 Hz to 500 kHz and within the temperature range from 300 K to 320 K. Dielectric constant e′(ω) and dielectric loss e″(ω) are found to be highly frequency (ω) and temperature dependent, and this behavior is interpreted on the basis of Guintini’s theory of dielectric dispersion. The ac conductivity (σac) is found to be temperature independent and obey the power law ωs, where s < 1 and decreases as temperature rises. The obtained results are discussed in terms of the correlation barrier hopping model proposed by Elliot. The composition dependence of the dielectric constant, dielectric loss and ac conductivity are also discussed and reported here.

Role of Cu additive on the dielectric relaxation of Se75Te25and Se85Te15glassy alloys

The effect of Cu additive on the dielectric relaxation of two binary Se-Te glassy systems, comparing the properties of a-Se 75 Te 25 , a-Se 85 Te 15 and a-Se 75 Te 15 Cu 10 alloys has been reported. The temperature and frequency dependence of dielectric parameters in Glassy Se 75 Te 25 , Se 85 Te 15 and Se 75 Te 15 Cu 10 alloys are studied by measuring capacitance and dissipation factor in the frequency range (1 kHz-5 MHz) and temperature range (300-350 K). A Debye like relaxation of dielectric behavior has been observed. A comprehensive study on the relaxation mechanism revealed that the presence of grains and grain boundaries across the pallet thickness is the basic relaxation process. A detailed analysis shows that the observed dielectric loss is in agreement with the Guintini's theory of dielectric dispersion based on two electron hopping over a potential barrier and is applicable in the present case. Dielectric constant ( e ’), dielectric loss ( e ”), loss tangent ( δ ) and capacitive reactance ( X c ) are found highly frequency and temperature dependent. Dependence of these dielectric parameters over the metallic impurity Cu, has also been found in the present glassy system and has been discussed in terms of electronegativity difference between the elements used in making the aforesaid glassy system.

An Action-at-a-Distance Theory of Gravitation

An action-at-a-distance theory is formulated as a possible alternative to the general theory of relativity. The observed gravitational frequency shift and light bending are obtained by photon energy and momentum conservation effects and gravitational–electromagnetic phenomena are interpreted in analogy with the quantum theory of dielectric dispersion. The observed perihelion advance of Mercury is obtained by a combined scalar and vector interaction theory of the Wheeler–Feynman type. The vector interaction is no longer excluded by conventional field theoretic arguments.

A note on the theory of dielectric dispersion in inhomogeneous dielectrics and semiconductors

A three-layer equivalent circuit for an inhomogeneous dielectric or semiconductor is described. This circuit can be used for describing dielectric dispersion in ferrites and other materials. Barrier layers, localized at inhomogeneities, are shown to be responsible for the low-frequency dispersion in ferrites.