A note on the temperature dependence of dielectric strength in supercooled liquids

摘要

The dielectric strength (Dgr;egr;=egr;0minus;egr;infin;) of dipolar liquid is often found to follow a simple relation of the form: Dgr;egr;=minus;A+B/T. In the present communication, the temperature dependence of Dgr;egr; in a large number of van derhyphen;Waals liquids has been investigated experimentally throughout the liquid range (from boiling temperature down to the glass transition temperature). Deviation from the above relation has been noticed in the supercooled state, only in the case of liquids which have a significant intramolecular contribution to polarization in true liquid state. The deviation is explained as due to a crossover to a mechanism which by necessity is predominantly, intermolecular in nature in the supercooled state. The present study indicates that this crossover is a result of increase in the liquid viscosity and is not due to any structural change. thinsp;