Switching in polystyrene films: Transition from on to off state

Experiments on polystyrene films formed by a glow-discharge technique shows a reproducible bistable switching. Various interpretations are briefly reviewed. It is shown that the resistance of the on state is strictly related to the energy needed by the on-off transition. From the value of this energy it is concluded that the most probable explanation is that the on current takes place along a filamentary path constituted by carbon atoms. A quantitative analysis is made on the basis of the heat balance equation. Formation of carbonated chains is confirmed by a chromatography analysis in vapor phase which shows an hydrogen release.