Electron thermalization distance distribution and ion mobility in n-C6F14

Abstract

Electron thermalization distances in liquid n-C6F14 were estimated from the electric field dependence of the free-ion yields at 0.3 ≤ E (MV/m) ≤ 3.7 and densities 1564 ≤ d (kg/m3) ≤ 1951; the latter correspond to 335.4 ≥ T (K) ≥ 191.3. The distance distribution function that best fits the data has a Gaussian body and power tail (YGP), the same as in n-alkanes and in C6F6 and SF6, but different from those in the liquids N2, CO, and CS2. The latter apparently capture electrons at higher energies than do the fluorine compounds. The static relative permittivity of liquid n-C6F14 was measured as a function of temperature and compared with the square of the refractive index and the Debye and Clausius–Mosotti equations. Atomic polarization appears to contribute 6% to the refractive index in the far infrared. Cation mobilities at temperatures 335.4 ≥ T (K) ≥ 191.2 are fitted by the free volume model, with v0 = 1.71 × 10−4 m3/mol and Ev = 3.24 kJ/mol. Keywords: electron, ion, liquid density, permittivity, mobility, n-C6F14, thermalization distance.