Dynamic Conductivity of Molten Salts. Part I: 3KNO3 · 2Ca(NO3)2 at Frequencies from 100MHz to 40GHz

Abstract

The dynamic ionic conductivity of the molten salt 3 KN03 · 2 Ca(NO3)2 has been measured at frequencies from 100 MHz to 40 GHz, at temperatures between 422 K and 478 K. Coaxial and rectangular waveguide systems have been used at 0.1 to 18 GHz and at 18 to 40 GHz, respectively. The conductivity is found to display the dispersion that is characteristic of the so-called “universal dielectric response". A similar dispersion was observed earlier at lower temperatures and frequencies. The data form arcs in the complex conductivity plane, with centers below the real axis. The modulus representation turns out to be comparatively involved and indirect, M″ featuring two maxima, while the conductivity data traverse a single arc in the complex plane. The present results are interpreted in terms o|f a non-Debye jump-relaxation model involving only one reorientational relaxation time. This time and its temperature dependence are close to those derived from other techniques.