Divergence of imaginary part of dielectric permittivity at the melting point in KC1

Abstract

The solid–liquid phase transition is a very common phenomenon, whose mechanism, although much studied, is not yet understood. A study of the properties of a solid having simple structure and simple bonding near the melting and the freezing point may be useful. We report the behaviour of the dielectric permittivity in KCl, a typical ionic crystal, in the microwave region in the vicinities of the melting and the freezing point. The imaginary part of the dielectric permittivity, ε", diverges at the melting and the freezing point; the real part, ε′, varies discontinuonsly. This supports a recent theory of melting, where the density fluctuations are emphasized as the precursors of melting or freezing.