Dielectric Constant and Molar Polarizability of Compressed Gaseous and Liquid Fluorine

Abstract

In this paper we present accurate wide‐range measurements of the dielectric constant of saturated liquid fluorine from 70 to 140°K and of compressed fluid fluorine at temperatures between 100 and 300°K at pressures to $\text{21\hspace{0.17em}}{\mathrm{MN/m}}^2\text{(1\hspace{0.17em}}{\mathrm{MN/m}}^2\text{=9.8692\hspace{0.17em}}\mathrm{atm}\text{=145.038\hspace{0.17em}}\mathrm{psi})$ . The data are combined with previously measured densities to determine the molar polarizability and its dependence on density and temperature. The density range examined extends to nearly 3 times the critical density. The molar polarizability is found to increase initially with density and then decrease. Current theories of the dielectric constant are found to give satisfactory qualitative interpretation of the density dependence of the molar polarizability but do not give satisfactory quantitative predictions.