Dielectric relaxation

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Relaxation is a process. The term applies, strictly speaking, to linear systems where a response and a stimulus are proportional to one another in equilbrium. Relaxation is a delayed response to a changing stimulus in such a system. Dielectric relaxation occurs in dielectrics, that is in insulating materials with negligible or small conductivity. The stimulus is almost always an electrical field, the response a polarization. The time lag between electrical field and polarization implies an irreversible degradation of free heat.

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.