A theory of electrical conductivity of molten salt

Abstract

The electrical conductivity of molten salt has been theoretically investigated starting from the linear response theory in view of a microscopic point. The velocity correlation functions in molten salt are expressed in terms of pair potentials and pair distribution functions in detail. Using these functions and generalized Langevin equations for the cation and anion of molten salt, the unified relations among the conductivity coefficients are obtained. In particular, it is shown that the ratio of partial conductivities, σ+/σ−, is equal to the inverse mass ratio, m−/m+. The friction constant of this molten salt is also expressed in terms of the pair potential and pair distribution function, by using the fluctuation dissipation theorem for random fluctuating force. Numerical results for molten alkali halides are presented and they are, more or less, the same order as the experimental results and computational ones.