Dielectric relaxation

Dielectric relaxation

Dielectric relaxation is the momentary delay (or lag) in the dielectric constant of a material. This is usually caused by the delay in molecular polarization with respect to a changing electric field in a dielectric medium (e.g. inside capacitors or between two large conducting surfaces). Dielectric relaxation in changing electric fields could be considered analogous to hysteresis in changing magnetic fields (for inductors or transformers). Relaxation in general is a delay or lag in the response of a linear system, and therefore dielectric relaxation is measured relative to the expected linear steady state (equilibrium) dielectric values. The time lag between electrical field and polarization implies an irreversible degradation of free energy(G).

In physics, dielectric relaxation refers to the relaxation response of a dielectric medium to an external electric field of microwave frequencies. This relaxation is often described in terms of permittivity as a function of frequency, which can, for ideal systems, be described by the Debye equation. On the other hand, the distortion related to ionic and electronic polarization shows behavior of the resonance or oscillator type. The character of the distortion process depends on the structure, composition, and surroundings of the sample.

The number of possible wavelengths of emitted radiation due to dielectric relaxation can be equated using Hemmings 1st Law

:n = frac{l^2-l}{2}

n: number of different possible wavelengths of emitted radiation
l: number of energy levels (inc. ground level)

See also

*Dielectric relaxation as a chemical rate process
* Debye relaxation
* Dielectric dispersion
* Dielectric spectroscopy
* Dielectric function

Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • dielectric relaxation — dielektrinė relaksacija statusas T sritis fizika atitikmenys: angl. dielectric relaxation vok. dielektrische Relaxation, f rus. диэлектрическая релаксация, f pranc. relaxation diélectrique, f …   Fizikos terminų žodynas

  • Dielectric relaxation as a chemical rate process — Dielectric relaxation was interpreted as a chemical rate process by Walter Kauzmann. According to Kauzmann, relaxation rates may be arranged in two or more distinct groups: Depending on how rapidly they change with temperature. In one group, we… …   Wikipedia

  • dielectric relaxation time — dielektrinės relaksacijos trukmė statusas T sritis fizika atitikmenys: angl. dielectric relaxation time vok. dielektrische Relaxationszeit, f rus. время диэлектрической релаксации, n pranc. période de relaxation diélectrique, f; temps de… …   Fizikos terminų žodynas

  • Relaxation time — is a general concept in physics for the characteristic time in which a system changes to an equilibrium condition from a non equilibrium condition. It can measure the time dependent response of a system to well defined external stimuli.… …   Wikipedia

  • Relaxation — may refer to: *Human relaxation is the art and science of doing nothing regardless of the outer activity including physical and/or mental tension. A human condition of flowing vital energy binging about a state of improved health and well being.… …   Wikipedia

  • Dielectric — A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their …   Wikipedia

  • Dielectric spectroscopy — A dielectric permittivity spectrum over a wide range of frequencies. The real and imaginary parts of permittivity are shown, and various processes are depicted: ionic and dipolar relaxation, and atomic and electronic resonances at higher energies …   Wikipedia

  • Relaxation (physics) — In the physical sciences, relaxation usually means the return of a perturbed system into equilibrium. Each relaxation process can be characterized by a relaxation time τ. The simplest theoretical description of relaxation as function of time t is …   Wikipedia

  • relaxation phenomenon — ▪ physics and chemistry Introduction       in physics and chemistry, an effect related to the delay between the application of an external stress to a system that is, to an aggregation of matter and its response. It may occur in nuclear, atomic,… …   Universalium

  • Dielectric dispersion — In physics, dielectric dispersion is the dependence of the permittivity of a dielectric material on the frequency of an applied electric field. Because there is always a lag between changes in polarization and changes in an electric field, the… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”