Dielectric examination of glass-forming systems. Part 2.—Chloronaphthalene in pyridine

Abstract

The dielectric properties of a complete range of concentrations of chloronaphthalene in pyridene have been investigated in the region of the solidification temperature. The temperature dependence of the characteristic loss frequency, the magnitude of the susceptibility and the Dissado–Hill shape parameters m and n have been measured and are reported.

It is shown that, as a function of concentration, there are three characteristic regions of behaviour. The experimental results indicate that at low concentrations of chloronaphthalene in pyridene a substitutional solid solution is formed. The limiting concentration of this solid solution is 20 mol %. For concentrations greater than 33 mol % a solid solution of pyridene in chloronaphthalene is obtained and in the intermediate range there is a mixture of two limiting structures. The approach of the system to the solidification temperature is examined and shown to be of the power-law form. The dielectric shape parameters were observed to be independent of temperature in both the α and β regions of response, with a transition between these regions in the neighbourhood of the solidification temperatures. It is shown that these parameters reflect the structure of the mixtures.