High mobility liquids as a result of competition between structural localization of electrons and reduction of polarization electron-atom attraction

According to the gas-kinetic approach excess electrons injected into a dense disordered medium (dense gas or liquid) must be inevitably localized. The free path of the electrons varies inversely as a scatterers density and with the fluid density increase it decreases and becomes comparable with electron wavelength. The electron is localized and its mobility falls. It is valid for the most molecular liquid; (liquid hydrocarbons) and for He, Ne and N₂ Nevertheless there are materials with a high electron mobility even in liquid state (Ar, Kr, Xe, methane, and neopentane). The peculiarity of these materials is a high polarizability of the atoms and the molecules. With a density increase a polarization attraction of an electron to an atom weakens and the electron free path grows. This phenomenon creates the “high-mobility dense media”. In fact the decrease of the polarization attraction does not have an original priority over the localization. The quasi-localization of excess electrons is observed in Kr and Xe. The electron mobility in these dense gases is lower than that extrapolated from a dilute gas region. With further gas density growth and transition of medium to liquid state the decrease of the polarization attraction leads to delocalization of electrons. Liquid Xe and Kr are real “high-mobility liquids”. These phenomena are illustrated by available experimental data. An external electric field influence on these phenomena, in particular the delocalization of electrons by the electric field, is also under consideration