Elementary charge carrier models for simple hydrocarbon liquids

While free electrons of relatively high mobility (similar 1 cm 2 V −1 s −1 ) have been observed in carefully purified hydrocarbons, the majority of published data refers to very low negative charge mobilities (10 −4 −10 −3 cm 2 V −1 s −1 ) associated with massive impurity carriers. It is believed that oxygen often constitutes the principal impurity and that the carrier consists of a negative oxygen ion entrapped in a cluster of polarized host-liquid molecules. The mean cluster size is evaluated and mobility values deduced using Stokes law. These predicted mobility values are in reasonably good agreement with experimental data. Moreover the carrier model and mobility determination techniques can be satisfactorily modified to account for the effect of polarizable impurities in the host liquid.