Jurgen Hocker

Long-term conductivity decrease in polyacetylene samples

Abstract Investigations of the conductivity decrease of polyacetylene samples doped with iodine, AsF 5 and FeCl 3 , respectively, and stored under various conditions (laboratory atmosphere, dry and humid air, vacuum, argon, argon at −30 °C) are reported. In laboratory atmosphere the conductivity drops by several orders of magnitude within a few weeks in samples prepared by the conventional Shirakawa technique. In argon atmosphere at −30 °C, after an initial drop by a factor of about two within a few days, the samples are very stable. With the exception of iodine doping, highly-doped samples are less stable in laboratory atmosphere or humid air than moderately-doped ones. Samples prepared by a new method from a polyacetylene suspension turn out to be much more stable than Shirakawa samples.