Distribution profiles of iron in FeCl3-doped polyacetylene films

The diffusion profiles of iron have been very accurately measured in polyacetylene films, during their doping process with FeCl₃, by using a radioactive isotope and a sectioning technique. Both in-diffusion from a labelled solution and out-diffusion towards an inactive solution have been studied. Saturation by thes dopant occurs at the mole fraction of 0.055. The crucial importance of the flow of dopant between the fibers is demonstrated. The rate of the isotopic exchange reaction is surprisingly high for a solid state reaction. These new data provide a better understanding of the doping mechanism.