Alternate formulation of dielectric data

Dielectric data itself is often presented as complex permittivities and susceptibilities. They are related as follows  

The complex impedance Z (co) of the sample is defined as the reciprocal of admittance and is equal to 1/T (co), which again reverts the emphasis on to a series process. 

We may note here for future discussion in this chapter that dielectric data is generally presented in a log-log form and a power function of co is used to represent x ( ) and related quantities  

The above function is known as universal law and can be seen to be equivalent to 

That the electric polarization (other than the instantaneous electronic part) of materials is due to the presence of electrical dipoles and that they respond to applied alternating electric field is a concept first introduced by Debye (1929). The Debye function is given by 

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