Dielectric Relaxation of Polar Liquids

The statistical theory of the dielectric relaxation of polar liquids is developed using the fluctuation-dissipation approach to linear dissipative phenomena, and an expression is derived relating the complex dielectric constant to a time-dependent microscopic correlation function. It is found that a finite number of microscopic relaxation times leads to an equal number of macroscopic decay times, and, in the case of a single relaxation time τ0, the decay time is given by T0=3ε0/(2ε0+ε∞)τ0,ε0 being the static dielectric constant, and ε∞ being the high frequency dielectric constant. Relaxation times are also determined for systems having two decay times, and for systems characterized by the circular-arc and skewed-arc distribution functions.